| 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 |
| Montour County | 18 236 | 17 735 | 501 | 2.8 |
| Anthony township | 1 388 | 1 287 | 101 | 7.8 |
| Cooper township | 966 | 934 | 32 | 3.4 |
| Danville borough | 4 897 | 5 165 | - 268 | - 5.2 |
| Derry township | 1 215 | 1 272 | - 57 | - 4.5 |
| Liberty township | 1 476 | 1 309 | 167 | 12.8 |
| Limestone township | 1 004 | 787 | 217 | 27.6 |
| Mahoning township | 4 263 | 4 134 | 129 | 3.1 |
| Mayberry township | 244 | 207 | 37 | 17.9 |
| Valley township | 2 093 | 2 010 | 83 | 4.1 |
| Washingtonville borough | 201 | 228 | - 27 | - 11.8 |
| West Hemlock township | 489 | 402 | 87 | 21.6 |
| Source: U.S. Census Bureau | Prepared by: Pennsylvania State Data Center | |||