| 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 |
| Bucks County | 597 635 | 541 174 | 56 461 | 10.4 |
| Bedminster township | 4 804 | 4 602 | 202 | 4.4 |
| Bensalem township | 58 434 | 56 788 | 1 646 | 2.9 |
| Bridgeton township | 1 408 | 1 378 | 30 | 2.2 |
| Bristol borough | 9 923 | 10 405 | - 482 | - 4.6 |
| Bristol township | 55 521 | 57 129 | - 1 608 | - 2.8 |
| Buckingham township | 16 442 | 9 364 | 7 078 | 75.6 |
| Chalfont borough | 3 900 | 3 069 | 831 | 27.1 |
| Doylestown borough | 8 227 | 8 575 | - 348 | - 4.1 |
| Doylestown township | 17 619 | 14 510 | 3 109 | 21.4 |
| Dublin borough | 2 083 | 1 985 | 98 | 4.9 |
| Durham township | 1 313 | 1 209 | 104 | 8.6 |
| East Rockhill township | 5 199 | 3 753 | 1 446 | 38.5 |
| Falls township | 34 865 | 34 997 | - 132 | - 0.4 |
| Haycock township | 2 191 | 2 165 | 26 | 1.2 |
| Hilltown township | 12 102 | 10 582 | 1 520 | 14.4 |
| Hulmeville borough | 893 | 916 | - 23 | - 2.5 |
| Ivyland borough | 492 | 490 | 2 | 0.4 |
| Langhorne borough | 1 981 | 1 361 | 620 | 45.6 |
| Langhorne Manor borough | 927 | 807 | 120 | 14.9 |
| Lower Makefield township | 32 681 | 25 083 | 7 598 | 30.3 |
| Lower Southampton township | 19 276 | 19 860 | - 584 | - 2.9 |
| Middletown township | 44 141 | 43 063 | 1 078 | 2.5 |
| Milford township | 8 810 | 7 360 | 1 450 | 19.7 |
| Morrisville borough | 10 023 | 9 765 | 258 | 2.6 |
| New Britain borough | 3 125 | 2 174 | 951 | 43.7 |
| New Britain township | 10 698 | 9 099 | 1 599 | 17.6 |
| New Hope borough | 2 252 | 1 400 | 852 | 60.9 |
| Newtown borough | 2 312 | 2 565 | - 253 | - 9.9 |
| Newtown township | 18 206 | 13 685 | 4 521 | 33.0 |
| Nockamixon township | 3 517 | 3 329 | 188 | 5.6 |
| Northampton township | 39 384 | 35 406 | 3 978 | 11.2 |
| Penndel borough | 2 420 | 2 703 | - 283 | - 10.5 |
| Perkasie borough | 8 828 | 7 878 | 950 | 12.1 |
| Plumstead township | 11 409 | 6 289 | 5 120 | 81.4 |
| Quakertown borough | 8 931 | 8 982 | - 51 | - 0.6 |
| Richland township | 9 920 | 8 560 | 1 360 | 15.9 |
| Richlandtown borough | 1 283 | 1 195 | 88 | 7.4 |
| Riegelsville borough | 863 | 912 | - 49 | - 5.4 |
| Sellersville borough | 4 564 | 4 479 | 85 | 1.9 |
| Silverdale borough | 1 001 | 881 | 120 | 13.6 |
| Solebury township | 7 743 | 5 998 | 1 745 | 29.1 |
| Springfield township | 4 963 | 5 177 | - 214 | - 4.1 |
| Telford borough | 2 211 | 1 673 | 538 | 32.2 |
| Tinicum township | 4 206 | 4 167 | 39 | 0.9 |
| Trumbauersville borough | 1 059 | 894 | 165 | 18.5 |
| Tullytown borough | 2 031 | 2 339 | - 308 | - 13.2 |
| Upper Makefield township | 7 180 | 5 949 | 1 231 | 20.7 |
| Upper Southampton township | 15 764 | 16 076 | - 312 | - 1.9 |
| Warminster township | 31 383 | 32 832 | - 1 449 | - 4.4 |
| Warrington township | 17 580 | 12 169 | 5 411 | 44.5 |
| Warwick township | 11 977 | 5 915 | 6 062 | 102.5 |
| West Rockhill township | 4 233 | 4 518 | - 285 | - 6.3 |
| Wrightstown township | 2 839 | 2 426 | 413 | 17.0 |
| Yardley borough | 2 498 | 2 288 | 210 | 9.2 |
| Source: U.S. Census Bureau | Prepared by: Pennsylvania State Data Center | |||