The aim of this study was to evaluate the efficacy of a new psychiatry clerkship curriculum which was designed to improve the knowledge and skills of medical students of Tehran University of Medical Sciences (TUMS), Iran.This quasi-experimental study was conducted in two consecutive semesters from February 2009 to January 2010. In total, 167 medical students participated in the study. In the first semester, as the control group, the clerks' training was based on the traditional curriculum. In the next semester, we constructed and applied a new curriculum based on the SPICES model (student-centered, problem-based, integrated, community-based, elective and systematic).At the end of the clerkship, the students were given two exams: Multiple Choice Questions (MCQ) to assess their knowledge, and Objective Structured Clinical Examination (OSCE) to assess their skills. Baseline data and test performance for each student were analyzed.Compared to the control group, students in the intervention group showed significantly higher OSCE scores (P= 0.01). With respect to MCQ score, no significant difference was found between the two groups.The results suggest that the revised curriculum is more effective than the traditional one in improving the required clinical skills in medical students during their psychiatry clerkship.