A 15‐year study of endometrial carcinoma in Louisville‐Jefferson County, Kentucky, revealed an increase of 26.3% in average yearly rates when the first 3 years, 1953‐1955, were compared with the last 3 years, 1965‐1967. An increase of 15.9% persisted when the rates were corrected for aging of the population; this was not statistically significant. Thus the mass cytologic screening program which had a beneficial effect on the rates for invasive cervix cancer, failed to have such an effect on endometrial carcinoma.