A study is made of 25 patients suffering from a vesicular prostate pathology causing sterility. We have assessed the age, profession, symptoms, genital exploration and ejaculation study including the amount, pH, visocity, fructose, ascorbic acid, count, motility and morphology of the sperms and the high leukocyte reading. A seminal liquid culture has been carried out on 21 patients, alone or in association with cultures of prostate and urine secretion following prostate massaging with positive results in 16 of them (76%). Treatment was begun on 22 patients, in 13 of whom the results are known. Spermiogram readings became normal in 5 (38%) with one pregnancy; there was an associated pathology in the wife in 3 cases. As antibacterians we have basically used trimetoprim-sulphametoxazol associated with erythromycin or not and sometimes, according to the antibogram, with other antibiotics, as well as drugs to clear the prostate area. The best results were obtained in astenozoospermias. The effectiveness of the treatment was equally due to the use of TMP-SMZ on its own or along with erythromycin. The other drugs have not improved the results, except for minocyclin which megativated a sperm culture. As a preliminary result the author presented three patients with sperm infection produced by E. coli at whom the titer of antibodies in serum was investigated.