Purpose: This study set its goals on determining 1) medical students personality types, 2) the correlation between medical students personality types and their satisfaction in medical school, 3) the correlation between medical students personality types and class achievements, 4) the correlation between medical students satisfaction in medical school and class achievements and 5) a proposition for using the results to benefit medical education. Methods: The study used the Korean version of Myers-Briggs Type Indicator (MBTI) GS form. This inventory was admisistered to the medical students during their orientation at the beginning of the first year of medical school. A total of 245 first year students in the years 2002 and 2003 completed the inventory. The study used the windows version of SPSS 11.0 statistics program. Results: The noticeable majority of medical students were introverted (68.2%) - Sensing (68.6%) - Thinking (71.4%) - Judgers (60.0%). Comparing personality types with satisfaction in medical school and satisfaction in medical school with class achievements showed no significant correlation. There was, however, a significant difference seen in comparing personality types with students achievements. Judging-type students showed higher class achievements (3.2) than perceptive-type (2.7), and SJ types showed higher class achievements (3.3) than SP types (2.6). Conclusion: The results of this study were consistent with previous studies done using Korean college students as subjects. And as the ISTJ type is appropriate for jobs related to medical care, the majority of medical students seem to have found their adequate career path. Implications for teaching and learning strategies, and for using the results of MBTI in medical students career planning are discussed.