Introduction Qualified and competent doctors in Indonesia has been produced for at least six years. At the end of their study they must be assessed by A High-Stakes National level examination called UKMPPD (Uji Kompetensi Mahasiswa Program Profesi Dokter) to assure national health quality services. There are two kind of asessments: cognitive will be asessed by MCQ-CBT, meanwhile skills and attitude will be measured by OSCE. There was many ways to enhance skills and OSCE UKMPPD passing score. One of effort from school of medicine UMY is using mentorship. This Study was conducted to analize whether OSCE mentorship can be effective to pass on OSCE UKMPPD. Methods This study used a pre-post experimental design with 153 participants who followed OSCE UKMPPD for period January-October 2017. Pre-test has been held 1 month before final exam with local comprehensive OSCE. The mentorship conducted in 1 month with 20 times departemental expert lectures, 40 times regulated independent learning OSCE and one time for formative simulated OSCE with direct feedback. OSCE UKMPPD result has been recorded as a post-test. Minimum requirement score for both of these test was more than 65. The data than analized using chi-square. Results There were significantly increased between pre and post test (p <0,05). Range of increasing result is was 0,52-29,63 and mean was 13,19 6,1. Highly increased of pre and post test result belongs to low-grade students who sucessfully pass the OSCE UKMPPD. There were two high-grade students (score >78) successfully passed this exam with lower increase of pre and post result (0,52;0,73). Generally there was improvement in passing score between local comprehensive OSCE and OSCE UKMPPD which was 54% to 98%. Discussion & Conclusions General Medical Council (2015) was reviewing about guidance for students to prepare for exams. This should include preparation countdown with key dates and preparation on finals. Therefore, School of Medicine UMY has conducted mentorship and the result showed that OSCE mentorship was effectively improves for passing on OSCE UKMPPD. The qualitativaly reasonable advantages of mentorship has been reported by Puspa Dewi et al. (2016). As a small discussion group, mentorship could bring motivational environment with constructive feedback and closely relationship between mentor and mentee. A qualitative study might be held latter for identify the real reason that may cause the significantly increase passing score of OSCE UKMPPD on School of Medicine UMY.