The aim of this research was to assess advantages and disadvantages of the modified version of PBL in Medicinal chemistry laboratory courses Method: This research was a self-control trial which means that the training method in the previous semester (non-PBL) was used as control. Seventy three students reflected the effectiveness of applying the modified version of PBL on a 19 item questionnaire. The reliability and validity of the questionnaire was confirmed by Cronbach- alpha test (r=0.72) and experts, opinions respectively. Collected data was analyzed by using ANOVA and T-test (p<0.05). Results: The students believed that using the pre-lab questionnaire increased rate of experience and comprehension, reformed problems and study before the class session 69.6%, 74.6%, 79%, 66% respectively. It reduced errors in experience resulted (65.8%) and prepared sufficient guideline on how to write the details (67%). Conclusion: pre-lab questionnaire via PBL method stimulated students’ activities and achievements in the learning process.
Key words: Problem-based Learning, Science Education, Medicinal Chemistry Laboratory, Pharmacy students