The fact that about one-half of students who enrolled for the bachelor study leave the university before obtaining the degree can be observed at universities worldwide. Factors of students’ dropout can be studied either by surveys among students or by analyzing data the university collects. In the work reported in the paper, we analyzed data about students who enrolled for the bachelor study in the academic year 2013/14. We created several decision trees with the aim to predict who will finish the study successfully and who will not. Using data collected on a semester basis, we found out that the most important variable is the percentage of lost credits in the most recent semester.