| 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 |
| Cumberland County | 213 674 | 195 257 | 18 417 | 9.4 |
| Camp Hill borough | 7 636 | 7 831 | - 195 | - 2.5 |
| Carlisle borough | 17 970 | 18 419 | - 449 | - 2.4 |
| Cooke township | 117 | 90 | 27 | 30.0 |
| Dickinson township | 4 702 | 3 870 | 832 | 21.5 |
| East Pennsboro township | 18 254 | 16 588 | 1 666 | 10.0 |
| Hampden township | 24 135 | 20 384 | 3 751 | 18.4 |
| Hopewell township | 2 096 | 1 913 | 183 | 9.6 |
| Lemoyne borough | 3 995 | 3 959 | 36 | 0.9 |
| Lower Allen township | 17 437 | 15 254 | 2 183 | 14.3 |
| Lower Frankford township | 1 823 | 1 491 | 332 | 22.3 |
| Lower Mifflin township | 1 620 | 1 700 | - 80 | - 4.7 |
| Mechanicsburg borough | 9 042 | 9 452 | - 410 | - 4.3 |
| Middlesex township | 6 669 | 5 780 | 889 | 15.4 |
| Monroe township | 5 530 | 5 468 | 62 | 1.1 |
| Mount Holly Springs borough | 1 925 | 1 925 | 0 | 0.0 |
| Newburg borough | 372 | 312 | 60 | 19.2 |
| New Cumberland borough | 7 349 | 7 665 | - 316 | - 4.1 |
| Newville borough | 1 367 | 1 349 | 18 | 1.3 |
| North Middleton township | 10 197 | 9 833 | 364 | 3.7 |
| North Newton township | 2 169 | 1 779 | 390 | 21.9 |
| Penn township | 2 807 | 2 425 | 382 | 15.8 |
| Shippensburg borough | 4 467 | 4 328 | 139 | 3.2 |
| Shippensburg township | 4 504 | 4 606 | - 102 | - 2.2 |
| Shiremanstown borough | 1 521 | 1 567 | - 46 | - 2.9 |
| Silver Spring township | 10 592 | 8 369 | 2 223 | 26.6 |
| Southampton township | 4 787 | 3 552 | 1 235 | 34.8 |
| South Middleton township | 12 939 | 10 340 | 2 599 | 25.1 |
| South Newton township | 1 290 | 1 153 | 137 | 11.9 |
| Upper Allen township | 15 338 | 13 347 | 1 991 | 14.9 |
| Upper Frankford township | 1 807 | 1 703 | 104 | 6.1 |
| Upper Mifflin township | 1 347 | 1 013 | 334 | 33.0 |
| West Pennsboro township | 5 263 | 4 945 | 318 | 6.4 |
| Wormleysburg borough | 2 607 | 2 847 | - 240 | - 8.4 |
| Source: U.S. Census Bureau | Prepared by: Pennsylvania State Data Center | |||