Approximately 80–90% of adult ovarian cancers are assumed to originate from ovarian surface cells. The morphology of the ovarian surface epithelium changes constantly, exhibiting features such as crypts, inclusion cysts, villous processes and different forms of mÜllerian epithelium. The unique nature of ovarian surface features and their absence in the immediately adjacent peritoneal mesothelium suggest that local factors may play an important part in modifying the growth and morphology of the ovarian surface epithelium. Recent studies tend to emphasize oncogene activation, along with concomitant cytogenetic changes, in the development of ovarian cancer. This review focuses on the roles of exogenous and endogenous factors and ovulation in the pathogenesis of ovarian cancer.