This study deals with personality variables of medical students in relation to their academic success in the preclinical stage. One hundred and one students completed the 16PF Questionnaire at the beginning of their medical course and the scores were analysed in relation to their marks obtained at the end of the 2-year preclinical stage. This study shows that the 16PF Questionnaire can be a useful instrument for identifying personality variables in candidates who are likely to have academic problems and those who are likely to do well in the preclinical stage of a medical course. Students of urban origin and the eldest in the family performed better in their preclinical years. Performance was not related to sex, ethnic group, family size of entrance qualification into medicine. Personality variables of being enthusiastic, venturesome, self-opinionated, imaginative, experimenting, resourceful and driven correlate positively with performance, whereas being self-assured has negative correlation. Problem students were more reserved, emotionally less stable and more apprehensive than non-problem students.