OBJECTIVES Many factors influence the career specialty decisions made by medical students. The aim of this study was to broaden consideration of the determinants of specialty choice in a large population of medical students in their sixth year of study. METHODS A total of 2588 students distributed across all of the 39 medical schools in France participated in a National Practice Examination in December 2008, after which an electronic questionnaire was administered. Study criteria were: population characteristics; demographics, and motivation for and drawbacks to medical specialty choice. RESULTS A total of 1780 students (1111 women, 62%) responded to the questionnaire (69% response rate). The mean age of respondents was 23.8 years (22-35 years). Of these, 1555 students (87%) stated their preferred medical specialty. Surgical and medical specialties were the two specialties selected most frequently by students (n = 729, 47%). General practice was chosen by 20%. Gender influenced the choice of specialty: 88% of future paediatricians, 82% of gynaecologists and 77% of general practitioners (GPs) were women (p < 0.05). Main motivating factors included interesting diseases, opportunities for private practice and patient contact. Main drawbacks limiting the choice of other specialties were poor quality of life, an exclusively hospital-based career and loss of patient contact. Gender was the criterion most associated with significant differences in factors of motivation for or discouragement from a career. Patient contact and opportunities for private practice were significantly highlighted by future GPs compared with students opting for the medical or surgical specialties (p < 0.0001). CONCLUSIONS Students' career choices regarding specialties or general practice result from the interplay among several factors. Career interest in general practice is particularly low. Initiatives to address the factors affecting student career choices regarding less favoured specialties and to deal with the growing feminisation of the profession, which will lead to irreversible changes in clinical practice, are required.