Ejaculates were studied from ten men with severe psoriasis treated with topical corticosteroids and from ten similar patients who had received methotrexate therapy from 1 to 9 years. It was not possible to demonstrate any unfavorable effect on the semen quality during the methotrexate therapy. The semen analysis was more frequently found normal (p = 0.04) in the methotrexate treated group, and no specific abnormality was found in spermatozoa of methotrexate-treated patients. Methotrexate therapy to male psoriatics seems safe and in agreement with this no congenital abnormalities have been reported. A remarkable number of the ejaculates had reduced sperm qualities, and it is proposed that this might be due to psoriatic lesions in the genital tract.