Plasma androstenedione (A) levels and plasma oestrone (E1) levels were measured by radioimmunoassay in a total of 135 healthy women (the control group), around the menopause. Both A and E1 plasma levels were found to drop significantly in the post-menopausal women (P less than 0.001). The mean plasma levels of A and E1 found in these healthy women were compared with the same plasma levels found in a total of 96 hospitalized women who were found to have various gynaecological disorders. Out of the total 96 patients, 29 were post-menopausal and had adenocarcinoma of the endometrium. The mean plasma levels of A and E1 were not significantly different in comparison with the norm. The mean body weight of the tumour patients was slightly higher than the mean body weight of the healthy women. There were 25 other patients, around the menopause, who had glandular hyperplasia of the endometrium. The mean plasma levels of androstenedione found in these women were significantly higher than the mean levels found in the healthy group of women; both groups were similar in body weight. The oestrone levels found in these patients were within the normal range. The remaining 42 patients, around the menopause, were affected with dysfunctional uterine bleeding, without endometrial hyperplasia. The plasma androstenedione levels were within the normal range. Oestrone plasma levels were not measured in this group of women. This study investigates the possible differences found in the endocrine plasma levels of women with glandular hyperplasia and adenocarcinoma of the endometrium.