Polyamine content has been determined in the seminal plasma of unfertile men before and after S-adenosylmethionine treatment. Spermine and spermidine levels in azoospermic patients were found very low (80 and 24 microgram/ml) with respect to normospermic (1500 and 60 microgram/ml): S-adenosylmethionine treatment enhanced polyamine content (50-300%) in oligospermic patients. Furthermore, an increase of sperm count and motility has been observed in these patients.