Geography
The Region of Western Macedonia claimed its current form when the “Kallikratis Programme”, regarding New Architecture of Self-governing Entities and Deconcentrated Administration, officially entered into force (Law 3852/2010, Government Gazette 87/06.07.2010). Since then it consists of the Regional Units of Grevena, Kastoria, Kozani and Florina. The Region’s geographical boundaries are displayed on the following image. According to the 2011 census, the Regional Units’ population is the following:
| Region | Permanent Population | Men | Women | Density SQKM |
| Region of West Macedonia | 282120 | 141260 | 140860 | 29,85 |
| Regional Unit of Kozani | 149270 | 74610 | 74660 | 42,46 |
| Municipality of Kozani | 70420 | 35340 | 35080 | 65,74 |
| Municipality of Voio | 18510 | 9220 | 9290 | 18,37 |
| Municipality of Eordea | 45450 | 22620 | 22830 | 64,12 |
| Municipality of Servia-Velvendo | 14890 | 7430 | 7460 | 20,45 |
| Regional Unit of Grevena | 31490 | 16270 | 15220 | 13,75 |
| Municipality of Grevena | 25620 | 13330 | 12290 | 13,78 |
| Municipality of Deskati | 5870 | 2940 | 2930 | 13,6 |
| Regional Unit of Kastoria | 50280 | 25120 | 25160 | 29,23 |
| Municipality of Kastoria | 35830 | 17840 | 17990 | 46,94 |
| Municipality of Nestorio | 2630 | 1350 | 1280 | 4,27 |
| Municipality of Orestiada | 11820 | 5930 | 5890 | 34,69 |
| Regional Unit of Florina | 51080 | 25260 | 25820 | 26,54 |
| Municipality of Florina | 32620 | 15910 | 16710 | 39,8 |
| Municipality of Aminteo | 16890 | 8570 | 8320 | 28,66 |
| Municipality of Prespes | 1570 | 780 | 790 | 3,05 |
Provisional data from the census released by ELLSTAT in 2011
