| COUNTY | Population Under 18, 2000 | Percent Change 1990-2000 | Percent of Total Population, 2000 | Percent Under 18 Multiracial, 2000 | White | Black | American Indian | Asian | Hawaiian/ Pac. Islndr. | Other | Multiracial | HISPU18 | pchisp9000 |
| Adair | 4,796 | -3.0 | 19.2 | 1.5 | 4,596 | 44 | 16 | 38 | 1 | 28 | 73 | 88 | 66.0 |
| Andrew | 4,348 | 9.9 | 26.4 | 0.7 | 4,252 | 26 | 21 | 11 | 0 | 9 | 29 | 56 | 47.4 |
| Atchison | 1,547 | -7.0 | 24.1 | 0.5 | 1,435 | 91 | 1 | 3 | 0 | 9 | 8 | 20 | 5.3 |
| Audrain | 6,360 | 2.6 | 24.6 | 1.8 | 5,738 | 437 | 11 | 27 | 4 | 31 | 112 | 66 | 106.3 |
| Barry | 8,875 | 27.0 | 26.1 | 2.0 | 8,132 | 14 | 84 | 29 | 4 | 435 | 177 | 708 | 1041.9 |
| Barton | 3,445 | 15.4 | 27.5 | 2.0 | 3,303 | 20 | 27 | 13 | 3 | 10 | 69 | 48 | 84.6 |
| Bates | 4,419 | 13.5 | 26.5 | 1.3 | 4,256 | 28 | 37 | 5 | 1 | 36 | 56 | 89 | 89.4 |
| Benton | 3,516 | 17.9 | 20.5 | 1.6 | 3,422 | 5 | 20 | 6 | 1 | 5 | 57 | 57 | 159.1 |
| Bollinger | 3,151 | 12.7 | 26.2 | 1.3 | 3,045 | 13 | 33 | 10 | 0 | 10 | 40 | 32 | 14.3 |
| Boone | 30,902 | 21.3 | 22.8 | 4.0 | 24,492 | 3,835 | 120 | 875 | 11 | 325 | 1,244 | 757 | 120.1 |
| Buchanan | 20,937 | -2.4 | 24.3 | 3.0 | 18,970 | 947 | 103 | 81 | 1 | 210 | 625 | 719 | 14.1 |
| Butler | 9,886 | -1.0 | 24.2 | 2.2 | 8,749 | 781 | 53 | 48 | 1 | 40 | 214 | 165 | 96.4 |
| Caldwell | 2,428 | 10.9 | 27.1 | 0.9 | 2,381 | 2 | 11 | 1 | 0 | 12 | 21 | 30 | 20.0 |
| Callaway | 10,371 | 20.7 | 25.4 | 2.3 | 9,523 | 480 | 54 | 28 | 2 | 44 | 240 | 130 | 103.1 |
| Camden | 7,508 | 24.9 | 20.3 | 1.9 | 7,238 | 22 | 46 | 30 | 3 | 30 | 139 | 111 | 60.9 |
| Cape Girardeau | 16,097 | 9.9 | 23.4 | 2.2 | 14,244 | 1,268 | 54 | 89 | 3 | 82 | 357 | 227 | 141.5 |
| Carroll | 2,589 | -7.8 | 25.2 | 1.5 | 2,478 | 55 | 11 | 4 | 0 | 2 | 39 | 27 | 35.0 |
| Carter | 1,493 | -2.2 | 25.1 | 1.9 | 1,427 | 2 | 33 | 1 | 0 | 1 | 29 | 40 | 263.6 |
| Cass | 23,307 | 25.1 | 28.4 | 2.3 | 21,963 | 390 | 159 | 115 | 9 | 142 | 529 | 754 | 115.4 |
| Cedar | 3,382 | 20.2 | 24.6 | 2.2 | 3,194 | 24 | 26 | 26 | 3 | 34 | 75 | 70 | 159.3 |
| Chariton | 1,997 | -15.7 | 23.7 | 0.5 | 1,929 | 48 | 3 | 3 | 0 | 5 | 9 | 18 | 500.0 |
| Christian | 15,114 | 60.4 | 27.8 | 1.9 | 14,562 | 65 | 72 | 44 | 5 | 85 | 281 | 294 | 200.0 |
| Clark | 1,852 | -9.6 | 25.0 | 0.9 | 1,813 | 4 | 9 | 1 | 1 | 7 | 17 | 25 | 150.0 |
| Clay | 47,530 | 20.0 | 25.8 | 3.3 | 42,642 | 1,605 | 216 | 692 | 52 | 770 | 1,553 | 2,505 | 100.2 |
| Clinton | 5,079 | 9.9 | 26.8 | 1.9 | 4,863 | 82 | 11 | 7 | 0 | 22 | 94 | 83 | 33.9 |
| Cole | 17,294 | 8.7 | 24.2 | 2.0 | 15,105 | 1,499 | 32 | 142 | 7 | 161 | 348 | 306 | 128.4 |
| Cooper | 3,801 | 5.0 | 22.8 | 2.0 | 3,483 | 199 | 12 | 12 | 0 | 18 | 77 | 38 | -2.6 |
| Crawford | 5,990 | 16.3 | 26.3 | 1.3 | 5,851 | 17 | 27 | 7 | 5 | 8 | 75 | 64 | 88.2 |
| Dade | 1,928 | 3.3 | 24.3 | 1.4 | 1,874 | 5 | 14 | 3 | 1 | 4 | 27 | 20 | -47.4 |
| Dallas | 4,302 | 26.3 | 27.5 | 2.0 | 4,167 | 8 | 26 | 2 | 3 | 10 | 86 | 64 | 166.7 |
| Daviess | 2,162 | 1.7 | 27.0 | 0.8 | 2,112 | 2 | 15 | 2 | 7 | 7 | 17 | 20 | 17.6 |
| DeKalb | 2,403 | 13.4 | 20.7 | 1.1 | 2,314 | 18 | 23 | 4 | 0 | 17 | 27 | 32 | 77.8 |
| Dent | 3,716 | 2.9 | 24.9 | 1.8 | 3,568 | 23 | 37 | 6 | 0 | 14 | 68 | 55 | 34.1 |
| Douglas | 3,382 | 6.4 | 25.8 | 1.7 | 3,265 | 7 | 33 | 7 | 0 | 13 | 57 | 40 | 11.1 |
| Dunklin | 8,613 | -1.4 | 26.0 | 1.8 | 7,032 | 1,240 | 27 | 19 | 2 | 140 | 153 | 371 | 415.3 |
| Franklin | 25,661 | 11.1 | 27.4 | 1.4 | 24,829 | 265 | 58 | 67 | 3 | 69 | 370 | 254 | 46.0 |
| Gasconade | 3,800 | 9.0 | 24.8 | 1.0 | 3,741 | 2 | 8 | 0 | 0 | 11 | 38 | 24 | 242.9 |
| Gentry | 1,782 | 6.8 | 26.0 | 0.8 | 1,747 | 4 | 7 | 4 | 4 | 2 | 14 | 19 | 46.2 |
| Greene | 53,501 | 12.1 | 22.3 | 3.1 | 48,649 | 1,517 | 417 | 657 | 33 | 557 | 1,671 | 1,528 | 160.3 |
| Grundy | 2,424 | -2.1 | 23.2 | 1.7 | 2,335 | 14 | 9 | 6 | 0 | 18 | 42 | 74 | 131.3 |
| Harrison | 2,103 | 9.5 | 23.8 | 1.9 | 2,038 | 6 | 6 | 4 | 3 | 5 | 41 | 40 | 233.3 |
| Henry | 5,220 | 6.4 | 23.7 | 1.6 | 4,969 | 73 | 46 | 13 | 4 | 32 | 83 | 89 | 30.9 |
| Hickory | 1,782 | 26.7 | 19.9 | 2.4 | 1,715 | 3 | 13 | 1 | 0 | 8 | 42 | 26 | 136.4 |
| Holt | 1,272 | -16.9 | 23.8 | 1.1 | 1,253 | 0 | 2 | 0 | 0 | 3 | 14 | 8 | 33.3 |
| Howard | 2,451 | 2.9 | 24.0 | 2.3 | 2,206 | 164 | 8 | 2 | 1 | 14 | 56 | 36 | 89.5 |
| Howell | 9,676 | 16.9 | 26.0 | 2.3 | 9,212 | 47 | 105 | 43 | 3 | 40 | 226 | 189 | 190.8 |
| Iron | 2,673 | -6.4 | 25.0 | 0.7 | 2,567 | 73 | 3 | 1 | 0 | 10 | 19 | 22 | 22.2 |
| Jackson | 168,766 | 4.9 | 25.8 | 4.0 | 102,916 | 50,453 | 800 | 1,938 | 418 | 5,486 | 6,755 | 12,314 | 91.8 |
| Jasper | 26,952 | 16.5 | 25.7 | 3.7 | 24,288 | 450 | 400 | 169 | 24 | 624 | 997 | 1,413 | 360.3 |
| Jefferson | 55,270 | 7.9 | 27.9 | 1.5 | 53,474 | 438 | 127 | 179 | 11 | 223 | 818 | 841 | 78.9 |
| Johnson | 12,124 | 16.6 | 25.1 | 3.8 | 10,626 | 607 | 99 | 110 | 9 | 209 | 464 | 513 | 95.8 |
| Knox | 1,087 | 2.3 | 24.9 | 1.7 | 1,062 | 1 | 0 | 0 | 0 | 5 | 19 | 13 | 225.0 |
| Laclede | 8,675 | 19.0 | 26.7 | 2.0 | 8,346 | 43 | 38 | 27 | 0 | 46 | 175 | 165 | 230.0 |
| Lafayette | 8,636 | 5.3 | 26.2 | 1.9 | 8,128 | 219 | 27 | 24 | 4 | 70 | 164 | 161 | 89.4 |
| Lawrence | 9,578 | 18.5 | 27.2 | 2.1 | 8,969 | 31 | 83 | 21 | 5 | 265 | 204 | 517 | 468.1 |
| Lewis | 2,627 | 9.7 | 25.0 | 1.8 | 2,469 | 79 | 2 | 4 | 0 | 27 | 46 | 33 | 3200.0 |
| Lincoln | 11,691 | 34.5 | 30.0 | 2.0 | 11,103 | 218 | 47 | 18 | 5 | 65 | 235 | 173 | 130.7 |
| Linn | 3,489 | 1.7 | 25.4 | 1.5 | 3,390 | 24 | 13 | 1 | 0 | 9 | 52 | 39 | 18.2 |
| Livingston | 3,553 | -3.0 | 24.4 | 1.5 | 3,430 | 37 | 8 | 7 | 1 | 17 | 53 | 39 | 85.7 |
| Macon | 3,820 | 1.5 | 24.2 | 1.6 | 3,611 | 102 | 18 | 6 | 1 | 20 | 62 | 51 | 96.2 |
| Madison | 2,904 | 1.8 | 24.6 | 0.9 | 2,853 | 6 | 3 | 5 | 0 | 10 | 27 | 25 | 8.7 |
| Maries | 2,318 | 12.0 | 26.0 | 1.7 | 2,229 | 17 | 11 | 4 | 0 | 18 | 39 | 46 | 130.0 |
| Marion | 7,269 | -3.6 | 25.7 | 2.6 | 6,586 | 425 | 23 | 17 | 9 | 21 | 188 | 88 | 109.5 |
| McDonald | 6,259 | 33.7 | 28.9 | 3.9 | 5,454 | 14 | 230 | 4 | 7 | 309 | 241 | 792 | 1265.5 |
| Mercer | 864 | 3.2 | 23.0 | 0.5 | 850 | 3 | 7 | 0 | 0 | 0 | 4 | 3 | 200.0 |
| Miller | 6,198 | 7.0 | 26.3 | 1.0 | 6,063 | 14 | 27 | 7 | 3 | 25 | 59 | 95 | 156.8 |
| Mississippi | 3,534 | -15.2 | 26.3 | 1.1 | 2,374 | 1,085 | 12 | 2 | 1 | 21 | 39 | 60 | 361.5 |
| Moniteau | 3,836 | 13.2 | 25.9 | 1.7 | 3,642 | 28 | 10 | 10 | 0 | 82 | 64 | 170 | 794.7 |
| Monroe | 2,410 | -4.0 | 25.9 | 1.5 | 2,238 | 113 | 9 | 2 | 1 | 12 | 35 | 23 | 35.3 |
| Montgomery | 3,085 | 3.6 | 25.4 | 2.8 | 2,908 | 67 | 7 | 6 | 0 | 11 | 86 | 40 | 90.5 |
| Morgan | 4,595 | 27.3 | 23.8 | 1.9 | 4,435 | 18 | 37 | 7 | 1 | 10 | 87 | 64 | 178.3 |
| New Madrid | 5,223 | -14.6 | 26.4 | 1.2 | 3,968 | 1,152 | 9 | 7 | 0 | 26 | 61 | 77 | 92.5 |
| Newton | 13,819 | 17.4 | 26.3 | 3.0 | 12,592 | 102 | 402 | 35 | 46 | 228 | 414 | 492 | 244.1 |
| Nodaway | 4,245 | -13.0 | 19.4 | 1.1 | 4,132 | 17 | 9 | 28 | 0 | 11 | 48 | 27 | -10.0 |
| Oregon | 2,515 | 11.6 | 24.3 | 2.9 | 2,346 | 4 | 88 | 3 | 0 | 2 | 72 | 46 | 360.0 |
| Osage | 3,437 | 3.3 | 26.3 | 1.5 | 3,365 | 9 | 4 | 2 | 0 | 5 | 52 | 27 | 50.0 |
| Ozark | 2,107 | 6.2 | 22.1 | 1.2 | 2,058 | 8 | 8 | 2 | 0 | 6 | 25 | 38 | 111.1 |
| Pemiscot | 6,015 | -10.7 | 30.0 | 1.5 | 3,539 | 2,296 | 18 | 21 | 1 | 52 | 88 | 142 | 317.6 |
| Perry | 4,715 | 1.4 | 26.0 | 0.9 | 4,603 | 5 | 14 | 39 | 2 | 9 | 43 | 37 | 19.4 |
| Pettis | 10,377 | 12.7 | 26.3 | 3.1 | 9,227 | 382 | 48 | 29 | 8 | 364 | 319 | 589 | 440.4 |
| Phelps | 9,442 | 12.0 | 23.7 | 2.8 | 8,706 | 199 | 60 | 149 | 8 | 58 | 262 | 178 | 69.5 |
| Pike | 4,293 | -1.6 | 23.4 | 2.0 | 3,963 | 193 | 5 | 6 | 1 | 39 | 86 | 64 | 36.2 |
| Platte | 19,026 | 24.2 | 25.8 | 3.3 | 16,933 | 805 | 81 | 290 | 47 | 236 | 634 | 749 | 75.4 |
| Polk | 6,947 | 29.4 | 25.7 | 1.7 | 6,692 | 38 | 48 | 10 | 3 | 35 | 121 | 157 | 185.5 |
| Pulaski | 11,338 | -6.6 | 27.5 | 5.9 | 8,361 | 1,598 | 121 | 165 | 43 | 379 | 671 | 768 | 6.7 |
| Putnam | 1,254 | 10.1 | 24.0 | 0.6 | 1,243 | 0 | 0 | 2 | 0 | 1 | 8 | 15 | 114.3 |
| Ralls | 2,429 | 8.1 | 25.2 | 0.9 | 2,375 | 25 | 3 | 2 | 0 | 1 | 23 | 10 | 42.9 |
| Randolph | 5,874 | -3.6 | 23.8 | 2.6 | 5,324 | 314 | 28 | 28 | 1 | 27 | 152 | 115 | 79.7 |
| Ray | 6,433 | 2.8 | 27.5 | 1.8 | 6,137 | 98 | 20 | 18 | 0 | 41 | 119 | 116 | 136.7 |
| Reynolds | 1,608 | -8.3 | 24.0 | 3.0 | 1,502 | 25 | 22 | 4 | 0 | 6 | 49 | 25 | 177.8 |
| Ripley | 3,352 | 1.4 | 24.8 | 1.4 | 3,252 | 1 | 43 | 8 | 0 | 2 | 46 | 47 | 46.9 |
| Saline | 5,773 | -1.8 | 24.3 | 3.1 | 4,965 | 351 | 30 | 29 | 11 | 208 | 179 | 410 | 425.6 |
| Schuyler | 1,027 | -1.7 | 24.6 | 1.2 | 1,004 | 0 | 1 | 5 | 0 | 5 | 12 | 8 | -33.3 |
| Scotland | 1,423 | 16.8 | 28.6 | 0.7 | 1,407 | 4 | 2 | 0 | 0 | 0 | 10 | 18 | * |
| Scott | 11,085 | -0.9 | 27.4 | 1.4 | 8,996 | 1,814 | 25 | 30 | 0 | 61 | 159 | 179 | 113.1 |
| Shannon | 2,199 | 8.8 | 26.4 | 3.2 | 2,076 | 6 | 42 | 0 | 0 | 4 | 71 | 32 | 113.3 |
| Shelby | 1,729 | -3.0 | 25.4 | 1.1 | 1,664 | 31 | 6 | 1 | 0 | 8 | 19 | 19 | 111.1 |
| Ste. Genevieve | 4,749 | 5.9 | 26.6 | 0.9 | 4,646 | 27 | 19 | 8 | 0 | 5 | 44 | 49 | 206.3 |
| Stoddard | 7,093 | -1.6 | 23.9 | 1.6 | 6,811 | 88 | 42 | 7 | 1 | 33 | 111 | 94 | 64.9 |
| Stone | 6,138 | 49.4 | 21.4 | 1.7 | 5,940 | 7 | 37 | 18 | 1 | 31 | 104 | 122 | 130.2 |
| St. Charles | 82,248 | 27.6 | 29.0 | 1.9 | 76,594 | 2,693 | 181 | 653 | 23 | 515 | 1,589 | 1,589 | 89.4 |
| St. Clair | 2,219 | 12.8 | 23.0 | 1.7 | 2,148 | 7 | 11 | 6 | 0 | 10 | 37 | 31 | 210.0 |
| St. Francois | 13,335 | 6.9 | 24.0 | 1.2 | 12,946 | 115 | 36 | 40 | 2 | 39 | 157 | 139 | 56.2 |
| St. Louis | 255,991 | 4.8 | 25.2 | 2.3 | 178,871 | 63,349 | 469 | 5,551 | 58 | 1,686 | 6,007 | 4,860 | 52.7 |
| St. Louis City | 89,657 | -10.2 | 25.7 | 2.8 | 25,564 | 59,005 | 242 | 1,389 | 22 | 937 | 2,498 | 2,058 | 45.2 |
| Sullivan | 1,807 | 30.8 | 25.0 | 2.0 | 1,678 | 3 | 3 | 3 | 1 | 82 | 37 | 207 | 1193.8 |
| Taney | 8,912 | 67.8 | 22.4 | 2.5 | 8,406 | 41 | 110 | 31 | 8 | 90 | 226 | 381 | 414.9 |
| Texas | 5,734 | -0.8 | 24.9 | 2.5 | 5,465 | 17 | 65 | 25 | 1 | 15 | 146 | 93 | 78.8 |
| Vernon | 5,436 | 9.7 | 26.6 | 1.5 | 5,193 | 68 | 49 | 15 | 4 | 27 | 80 | 67 | 59.5 |
| Warren | 6,586 | 19.6 | 26.9 | 1.4 | 6,253 | 135 | 32 | 19 | 1 | 55 | 91 | 128 | 93.9 |
| Washington | 6,205 | 1.7 | 26.6 | 1.5 | 5,994 | 45 | 45 | 12 | 1 | 14 | 94 | 60 | 66.7 |
| Wayne | 3,079 | 12.0 | 23.2 | 1.5 | 2,998 | 14 | 15 | 2 | 1 | 4 | 45 | 19 | 18.8 |
| Webster | 8,957 | 31.9 | 28.9 | 2.0 | 8,604 | 39 | 70 | 28 | 1 | 37 | 178 | 170 | 153.7 |
| Worth | 579 | -1.5 | 24.3 | 0.9 | 569 | 2 | 3 | 0 | 0 | 0 | 5 | 3 | -50.0 |
| Wright | 4,877 | 3.5 | 27.2 | 1.1 | 4,743 | 18 | 29 | 8 | 0 | 24 | 55 | 59 | 118.5 |
| MISSOURI | 1,427,692 | 8.5 | 25.5 | 2.5 | 1,147,976 | 205,116 | 6,792 | 14,485 | 977 | 16,548 | 35,798 | 42,630 | 100.4 |