Aims. Designing collaborative tasks have an important role in medical students teaching and preparedness for performing their professional activity. This study was to evaluate the effect of group testing on information maintenance in medical students.

  Methods. In this observational cross-sectional study, 40 forth semester medical students of physiology class were randomly divided into two A (n=16) and B (n=24) groups. At first, students from both groups answered to questions individually. Immediately after completing the exam as individuals, students from group B answered the same questions as first exam in groups of 2-3 students. On the next exam (4 week later), students from both groups answered a randomly selected subset of questions from first exam as individuals. The results were analyzed by paired student T-test.

  Results. Student retention of course content was significantly (p<0.03) lower in group A (13.86±0.63) in comparison to group B (15.02±0.45). The mean of student scores in group B in the first exam was 15.67±0.45 while it was 16.1±0.44 in the second exam. So, student performance was improved significantly when students completed the original examinations in groups.

  Conclusion. Collaborative testing in addition to be an assessment tool of students can be used as an effective strategy to enhance learning and team work training.