In order to assess the contribution of individual steroidogenic organs to over-all steroid biosynthesis, the basal plasma levels of six hormonal steroids, reflecting the function of gonads and adrenals, as well as both gonadotropins and prolactin, have been determined in 63 oligo- and/or asthenozoospermic men with palpable varicocele, confirmed in each case by sonography. The values obtained were compared with the results of a group of age-matched normospermic men without endocrine disorders. Insignificantly lower levels of testosterone accompanied by significantly lower levels of dihydrotestosterone, slightly decreased LH but increased FSH undistinguishable concentrations of cortisol in patients with varicocele were in agreement with previous findings. Higher levels of an exclusively adrenal androgen 11 beta-hydroxyandrostenedione in men with varicocele indicate increased activity of the adrenal cortex. Significantly higher basal levels of 17 alpha-hydroxyprogesterone in the patient group (p < 0.001), so far not unequivocally proved, evidence for suggested decreased enzyme activity of C17-20 lyase in the testis in at least some of men with varicocele.