The aim of this study was to investigate how reliably psychology students assessed their professional skills and knowledge. Participants consisted of 117 students and were from three groups, namely: beginners, intermediate and advanced. They were asked to evaluate their skills in different areas of psychology using a questionnaire. Their skills in describing psychologists’ practice in two cases were also evaluated. The student groups differed in their self-assessed skills: the advanced student group got the best results in different areas of psychology while the group of beginners got less good results. The self-assessment of competence correlated significantly with the number of earned credits in psychology studies and points given by the teacher in problem-solving tasks. The challenge of training was that even after four years of studies, about 20% of the students were still at the level of lay helpers. The psychology students assessed their knowledge and skills very reliably. Additionally, the questionnaire turned out to be a good tool for feedback to develop the training of psychology.