Measuring the Validity and Reliability of the modified Ottawa checklist in evaluating cases designed for CBL. Methods: Cases were created by faculty members before and after a faculty development program (FDP); their quality was assessed using a modified version of The University of Ottawa CB template for quality assurance of the CBL by two medical education experts and an expert matter consultant. Results: 8 cases were created by faculty members. There was a statistically significant increase in the mean scores of the cases constructed after the workshops. The mean increase in the cases' mean score using the modified Ottawa checklist was 8.417. There was moderate agreement between raters. Conclusion: the effect size of the FDP was significant, and the modified Ottawa checklist is a valid, reliable, and objective tool for revising cases created for CBL.