In this article the authors establish the key competencies that should be acquired by future teachers in the course of their undergraduate studies. They also develop a model of the factors for which they presume most significantly contribute to the development of the selected competencies. For the selection of competencies and predictors of their development they adapted the model of the REFLEX Project (2009-) in-line with relevant theories, projects and authors concerning the competencies of primary school teachers. In the empirical part, the authors, among others, prove as follows: (1) the grades of the future primary school teachers during study have only a very limited impact on the acquired competencies studied in the paper; (2) occupational values highly impact the development of all studied competencies; (3) greater inclusiveness of an individual in social networks has a positive impact and statistically significantly contributes to reaching all studied competencies. The authors agree that the future development of the curriculum for primary school teachers should seriously consider these findings. (Contains 3 tables and 5 footnotes.)