Objective: To conduct a systematic review of primary research in undergraduate medical education in Pakistan in order to evaluate PBL programs, examine outcomes and competencies influenced by PBL, and compare them with conventional learning (lecture based learning, LBL). Study Design: Qualitative content analysis. Place and Duration of Study: Rawalpindi Medical College, Rawalpindi, from June 2010 – February 2011. Methodology: Literature was searched using online resources. Studies evaluating outcomes influenced by PBL, or comparing PBL with lecture based learning (LBL) were selected. Due to heterogeneity, a qualitative content analysis was performed in which studies were classified according to the methods of assessment; results were then summarized by outcome and frequencies were calculated. Results: Eleven studies were included. Apart from knowledge acquisition, students gave high ratings to PBL in selected outcomes, alone, and in comparison with LBL. There was a disagreement among results of studies that evaluated knowledge acquisition alone. Conclusion: Based on student perceptions, PBL has many advantages. However, the results of this review are limited due to heterogeneity and methodological weakness of studies, specially the studies that compared exam scores to assess knowledge acquisition.