Out of 37 infertile men, 33 who were able to give two ejaculates by masturbation successively with a sixty minute interval, were studied. There was no significant change in sperm density in the second ejaculation whereas seminal volume decreased (P < 0.01) and sperm motility increased (P < 0.05) significantly. After a seven-day treatment with combination of prazosin (alpha-1-blocker) and terbutaline (beta-2-stimulator), the same successive ejaculates were obtained from only 27 of these patients. In this case sperm density and motility changed insignificantly, whereas seminal volume again decreased (P < 0.01) significantly. The changes in seminal parameters were not significant between the pre- and post-treatment first specimens and between the pre- and post-treatment second ones. In a short-term study there are not any alterations to observe. The favourable results with a long-term treatment, published by Japanese authors, require a confirmation by further studies.