Population (persons)
| 2005 | 2010 | 2011 | 2012 | 2013 |
| Atlantique | 881,916 | 1,039,554 | 1,073,709 | 1,108,944 | 1,145,295 |
| Oueme | 803,908 | 947,603 | 978,737 | 1,010,855 | 1,043,991 |
| Borgou | 796,647 | 939,043 | 969,896 | 1,001,724 | 1,034,561 |
| Littoral | 731,664 | 862,445 | 890,781 | 920,013 | 950,171 |
| Zou | 659,998 | 777,969 | 803,530 | 829,898 | 857,103 |
| Atacora | 604,403 | 712,437 | 735,845 | 759,992 | 784,905 |
| Collines | 589,559 | 694,939 | 717,772 | 741,326 | 765,627 |
| Couffo | 577,087 | 680,238 | 702,588 | 725,644 | 749,431 |
| Alibori | 573,245 | 675,709 | 697,910 | 720,812 | 744,441 |
| Plateau | 447,861 | 527,913 | 545,258 | 563,151 | 581,612 |
| Mono | 396,070 | 466,865 | 482,204 | 498,028 | 514,354 |
| Donga | 385,097 | 453,931 | 468,845 | 484,230 | 500,103 |