It seems relevant to use in medical studies a teaching method, ensuring the acquisition and the integration of the knowledge and their use in and out of context. The interactive teaching by small groups brings lot of advantages: better apprehension of the problems, the ease of communication, better self-confidence and humanization of medical care. The objective of our study is to evaluate the perception and the appreciation of problem based learning (PBL) by the students while comparing between the both methods PBL and lecture method. Methods We organized a workshop on mental health during two days. using PBL. 34 students participated in this atelier. The students passed at first a pre-test. Later they were brought to analyze cases, to emit hypotheses and at the end of the training, a session of return was realized to validate the work and distribute a scorecard as well as a post-test. Results 76, 5 % found that the PBL was interesting because it facilitated the acquisition of the knowledge. The students appreciated the role of the tutor in the PBL also, they noticed that the teachers are more involved in this method compared to the lecture method. A significant improvement of the results of the test after the application of PBL. Conclusion The current situation implies that the students get synthetic vision of the big pathological processes, that they are able to have clinical and therapeutic reasoning, and to evolve a critical mind.