The histology, estrogen (ER)- and androgen (AR)- receptor content, s-FSH, s-LH, s-17-beta-estradiol, U-17-ketosteroid and U-17-ketogenic steroid patterns were measured in a consecutive series of 20 patients operated on for gynecomasty. Two out of 22 specimens were ER-positive, and 4 out of 22 were AR-positive. No relationship was demonstrated between the histopathologic features, ie. active-intermediate-inactive gynecomasty, and the steroid receptor content in the present limited number of cases. In addition, there was no marked relationship between the histopathologic features and the hormone values.