This study investigates the joint impact of personality characteristics and self-efficacy on the perceived academic achievement of medical students on top of their prior high school performance. The sample consisted of medical students in their pre-clinical years. The students' grade point average scores at high school were included as control variable in our explanatory models. Based on previous findings in the literature, we selected self-discipline, social activity and emotional stability from the Five Factor Model of Personality as predictor variables. Furthermore, following the social cognitive theory of Bandura, we added self-efficacy (students' belief in their academic skills) as an additional predictor. The logistic regression analyses confirmed the importance of self-discipline (positively related) and social activity (negatively related) for these students' perceived academic achievement. Additionally, we found a positive contribution of self-efficacy. The results of this study (as discussed in the final sections) have implications for support programmes in the practical field.