In order to analyze academic achievement of medical students and its related factors, a total of 2,371 students who entered the premedical course of O university from 1987 were reviewed based on cohor t of their admission year. Those who did not promoted to medical college from premedical course in two years were 15% and those who did not graduate medical school in four years were 21%. The percentage of female students and outside Seoul residents has been growing. The percentage that students parents occupation is medical profession has been decreasing. Those who failed during premedical course have higher conditional probability to fail during the medical studies. The results suggest that medical educators pay more attention to those who failed during the premedical course. Also the criteria whether students are failed or promoted to next grade is reasonable should be studied in depth.