Ovarian cancer is among the five leading sites for cancer incidence and mortality in women from developed countries. Its incidence and mortality rates have, however, been declining over the last few decades following the introduction of oral contraceptives, which - together with parity - are the best recognized protective factor for the disease. Late menopause and irregular menstrual cycles may also reduce the risk, while the role of hormone replacement therapy in menopause and fertility treatments is still unclear. Cosmetic talc use and some aspect of diet (i.e. saturated fats, refined carbohydrates) have been associated with increased risk, in some--though not all--studies), while vegetable consumption appears to be inversely related to risk. These issues remain open to debate. Women with a family history of ovarian and breast cancer in first-degree relatives are also at increased risk, but family history accounts for only 4-5% of cases. Most ovarian cancers are therefore environmental in origin and consequently, at least in principle, avoidable.