Follicle stimulating hormone (FSH) levels in semen are lower than in blood without any correlation to sperm counts while seminal luteinizing hormone (LH) levels are higher than in blood though with minor values in oligozoospermia and azoospermia conditions. In addition, the FSH levels in semen appear well correlated to those in blood; this type of correlation emerges for LH only in azoospermic patients. The mechanisms which facilitate LH to enter into the semen could be uneffective when spermatogenesis is impaired. If so, undetectable levels of both FSH and LH in semen would indicate obstructive forms of azoospermia while increased levels of LH would indicate the return of a hormonal spermatogenic process in patients undergoing treatment for infertility conditions.