There is general agreement that medical school curricula should involve the teaching of preventive health behaviours. Locus of control is a personality variable that has been associated with health practices and may be associated with tendencies to promote health practices. Few significant relationships have been found correlating health locus of control beliefs with preventive health behaviours. This study investigated the health locus of control of medical students and their tendencies to talk about and teach breast self-examination to women patients. Women students' health locus of control and breast self-examination practices were also investigated. The authors conclude that health locus of control has little influence on the tendency of medical students to promote breast self-examination. Other factors apparently have more effect on the student doctor's tendencies to promote health practices.