Trends in ovarian cancer incidence and mortality were examined using data from the Danish Cancer Registry and national mortality statistics respectively. The study population comprised 17,956 incident cases diagnosed between 1943 and 1982 and 11,904 deaths between 1953 and 1982 due to cancer in the ovaries, Fallopian tube, and broad ligament. A significant 50% increase in incidence occurred from 1943 to 1972, whereafter a slight decrease was observed. This rise could be ascribed entirely to an increasing incidence among women born between 1863 and 1898. No change was seen in women born after 1900. Analysis of mortality confirmed the increasing ovarian cancer risk among women born during the last century, but indicated that the risk of dying from ovarian cancer decreased with time among women born after 1900. The observed trends were compatible with cohort-specific changes in fertility in Danish women born between 1890 and 1934. The effect of age on ovarian cancer incidence, overall and by histologic type, agreed well with previous findings.