Excluding cases associated with oral sequential contraceptives, adenocarcinoma of the endometrium in young women is rare, constituting about 3% of endometrial carcinomas. The present report, based on findings from one institution, notes that women 40 years of age or younger comprised 14.4% of the 111 patients with adenocarcinoma of the endometrium. Factors analyzed in patients 40 years of age or younger (group A) as compared with those 41 years of age or older (group B) include the following: obesity 43.8% (A) versus 17.9% (B), nulliparity 44% (A) versus 10.5% (B), hypertension 31.2% (A) versus 42.1% (B), and diabetes 6.2% (A) versus 21.1% (B). Patients in group A tended to have a well-differentiated tumor, and 31.2% had polycystic ovaries. Awareness of risk factors in young women who develop endometrial adenocarcinoma leads to earlier diagnosis and will preserve the historically excellent survival rate of young women.