OBJECTIVE To examine ovarian cancer incidence and mortality in the Netherlands, and to relate trends in mortality to changes in parity and use of oral contraceptives. METHODS Age-standardized and age-specific incidence and mortality rates are presented using incidence data from the Netherlands Cancer Registry, 1989-1991, and mortality data from the Netherlands Central Bureau of Statistics, 1954-1993. RESULTS In the period 1989-1991, age-standardized incidence of ovarian cancer was 14.9 per 10(5) woman-years. The majority (89%) of these tumors had an epithelial origin. Two-thirds of all newly diagnosed ovarian cancers already showed extension to the pelvis or beyond at diagnosis. From the period 1954-1958 to 1969-1973, age-standardized mortality rates increased from 10.6 to 13.1 per 10(5) woman-years. Thereafter, a decline was noted to 11.4 per 10(5) woman-years in the period 1989-1993. Age-specific mortality rates showed a pattern of rising mortality in the elderly, whereas mortality in the younger age categories was declining. The number of live births has declined gradually, and oral contraceptive use has increased. CONCLUSIONS Incidence of ovarian cancer is high in the Netherlands, but comparable to other countries in north-western Europe and North America. Mortality rates are rising in the elderly and declining in the young. Further research is needed concerning the effects of oral contraceptives, fertility drugs, and hormone replacement therapy on the incidence and mortality of ovarian cancer.