The analysis of the results of externally evaluated school tests in Poland leads to rather surprising conclusions. The educational gap between urban and rural areas is smaller than expected. In turn, one can observe significant differences in educational quality among the historically defined districts of Poland. Those differences tend to be stronger within rural areas than between cities. In general the average test scores achieved in Western and Northern Poland are lower than those of students in former Galicia and Kongresówka. The model presented in this article shows that family education is the major determinant of local educational quality. The importance of this factor is higher in urban environment than in rural areas, where school achievements are also influenced by the accessibility of school resources. The regional differentiation of educational quality may be in part explained by high unemployment and social pathologies in the areas that suffered from the collapse of large state owned farms in early 90's. However, even with corresponding variables included in the model, most of the interregional gap in school achievements remains unexplained, leaving open field for further research.