Objectives:
The aim of the article is analysis the causes of differences in the regional development of Greater Poland and Warmia and Mazury.

Material and methods:
The study used the methodology used in the science of politics and administration, using the comparative method, the systemic method and the historical method.

Results:
The disproportions between dynamically developing areas and territories that cannot keep up with development are noticeable. The progressive polarization in this area requires analysis to explain the etiology of this phenomenon. The example of Wielkopolska and Warmia and Mazury clearly shows the differences in the development of the region which is the center and the peripheral region.

Conclusions:
Wielkopolska and Warmia and Mazury are characterized by significant differences in the level of regional development. This is due to many factors. Historical conditions and geographical location of both regions play an important role. Another group of factors is the specificity of regions, which is determined by the topography, demography, degree of urbanization and the condition of economic and road infrastructure. The analysis of etiological factors may be the starting point for considerations about the possibilities of eliminating regional differences.