Background and Objectives: Medical schools across Pakistan are shifting from pure knowledge based assessments to competency based evaluations. The emphasis is to evaluate something more than what a student knows. Objective structured clinical examination is an assessment of student skills and is being involved in the undergraduate curriculum on both a formative and summative basis. Summative OSCE evaluations have long been evaluated through the checklist method as it is felt to give a detailed point to point evaluation of the students performance. We in our study compared the two methods of OSCE rating (global rating and checklist method) in predicting the actual performance (final scores) of the students. Subjects: Final year medical students of Shifa College of medicine, Islamabad, Pakistan. Methods: Seventy seven students underwent through a series of ten OSCE stations in the subject of obstetrics and Gynecology. These students were rated by the global rating and the checklist method. Student scores by these two methods were regressed against their final score to see any correlation Results: Global and checklist rating had significant correlation with the final student score. But when forward regression was calculated, in which Marks A and B were regressed against dependent variable (final score).Marks A stood as a significant predictor of final score. (P value <0.001). R- square of Marks A was 0.223. Hence: Final score = 223.86+(1.918 X Marks A) Conclusion: Global rating of student OSCE provides a much better assessment of the students knowledge and skills.