A log-linear model was used to separate age, secular, and cohort trends in the incidence of cancer of the breast, ovary, corpus uteri, cervix uteri, vagina, and vulva in female residents in Alberta over the period 1953 to 1977. The age trends are similar for each cancer site increasing sharply in the premenopausal period and then leveling off. In the case of breast cancer, a point of inflection at the menopause (Clemmesen's hook) persists. A gradually increasing secular trend in incidence was evident for all sites except cervix uteri, the incidence of which declined after 1960. Cyclical cohort trends were found for cancers of the breast, ovary, and corpus uteri, inversely correlated with early fertility. The cohort trends for cervix uteri, vagina, and vulva increased sharply for cohorts born after 1940.