Purpose: This study explored the interrelationships between perfectionism, achievement goals, and academic efficacy, hypothesizing that perfectionism and achievement goals affected academic efficacy in medical students. Of the 400 medical students surveyed from three universities in Seoul, 228 completed and returned the questionnaires yielding a total response rate of 57%. Their average age was 23.28 years. Methods: Measures of students perfectionism, achievement goals, and academic efficacy were obtained. Exploratory factor analyses were used to measure dimensions of perfectionism (adaptive and maladaptive) and achievement goals (mastery, performance-approach, and performanceavoidance). Both scales confirmed the three subscales of achievement goals and two subscales of perfectionism through Principal Component Analyses and internal consistency testing. Structural quation modelling techniques were used to test the relationships among the variables. Results: It was found that adaptive perfectionism positively influenced students academic efficacy directly and indirectly via their mastery and performance-approach goals. Moreover, maladaptive perfectionism influenced their academic efficacy indirectly via their performanceapproach goals. However, maladaptive perfectionism did not influence their academic efficacy directly or indirectly via performance-avoidance goal. Conclusion: Medical educators need to be aware that encouraging students toward adaptive perfectionism, which is psychologically less stressful, is valuable given these findings. Perhaps learning environments could be developed to enhance students adaptive perfectionism, mastery and performance-approach goals, and subsequently academic efficacy.