The relationship between stages of the spermatogenic maturation process and male hormone levels was evaluated in 41 azoospermic, infertile men. Patients were categorized into groups according to the most mature spermatogenic cell type present in testicular aspirates: spermatocytes, spermatids or spermatozoa. High FSH and LH plasma levels were found in those with spermatocytes. Their hormone levels differed statistically (p < 0.005) from those in patients with maturation arrest at the spermatid stage, or those with spermatozoa in their testes. No statistically significant differences were found between the 3 groups with regard to plasma levels of testosterone, free testosterone and prolactin. However, there were positive correlations, higher for free testosterone than for testosterone, with stage of spermatogenic maturation.