| Population Change 1990-2000 | ||||
| County or Municipality | 2000 Population | 1990 Population | Population Change | Percent Change |
| Pennsylvania | 12 281 054 | 11 881 643 | 399 411 | 3.4 |
| Franklin County | 129 313 | 121 082 | 8 231 | 6.8 |
| Antrim township | 12 504 | 10 107 | 2 397 | 23.7 |
| Chambersburg borough | 17 862 | 16 647 | 1 215 | 7.3 |
| Fannett township | 2 370 | 2 309 | 61 | 2.6 |
| Greencastle borough | 3 722 | 3 600 | 122 | 3.4 |
| Greene township | 12 284 | 11 930 | 354 | 3.0 |
| Guilford township | 13 100 | 11 893 | 1 207 | 10.1 |
| Hamilton township | 8 949 | 7 745 | 1 204 | 15.5 |
| Letterkenny township | 2 074 | 2 251 | - 177 | - 7.9 |
| Lurgan township | 2 014 | 2 026 | - 12 | - 0.6 |
| Mercersburg borough | 1 540 | 1 640 | - 100 | - 6.1 |
| Metal township | 1 721 | 1 612 | 109 | 6.8 |
| Mont Alto borough | 1 357 | 1 395 | - 38 | - 2.7 |
| Montgomery township | 4 949 | 4 558 | 391 | 8.6 |
| Orrstown borough | 231 | 220 | 11 | 5.0 |
| Peters township | 4 251 | 4 090 | 161 | 3.9 |
| Quincy township | 5 846 | 5 704 | 142 | 2.5 |
| St. Thomas township | 5 775 | 5 861 | - 86 | - 1.5 |
| Shippensburg borough | 1 119 | 1 003 | 116 | 11.6 |
| Southampton township | 6 138 | 5 484 | 654 | 11.9 |
| Warren township | 334 | 310 | 24 | 7.7 |
| Washington township | 11 559 | 11 119 | 440 | 4.0 |
| Waynesboro borough | 9 614 | 9 578 | 36 | 0.4 |
| Source: U.S. Census Bureau | Prepared by: Pennsylvania State Data Center | |||