Six microsomal population of estradiol and androgen receptors have been characterized in human benign prostatic hypertrophy (BPH) and prostate cancer (PCa). Estradiol receptor (ER) and androgen receptors (AR) were extracted using 0.6 M KCL and determined by the dextran-coated charcoal method. ER and AR levels were smaller in BPH plasma membranes (PM) than in Pca cases. For functions 3, 4, 6, the ER values in PCa were 25-38% less with regard to BPH ER values. Whereas in PCa, AR values obtained in all fractions were higher when compared to BPH AR values. In benign prostatic hypertrophy and prostatic cancer, ER and AR levels were significantly higher in the nuclear fraction. In the nuclear fraction, ER and AR levels in BPH and PCa were significantly different. The subcellular distribution of AR and ER in BPH and PCa constitutes a reservation mechanism and processing a receptors for their continued growth.