The paper reports on the response to gonadotrophic hormone treatment in cases of male infertility. The report includes 119 cases treated between 1971 and 1975. The evaluation of the results of gonadotrophic hormone treatment led to the following conclusions. Treatment with Praedyn has been relatively successful and the rate of success was directly dependent on the number of applied ampoules. Pergonal 500 brought a considerable improvement in all the treated patients. A meaningful comparison of the effect of Praedyn and Pergonal 500, respectively, was not possible because of the relatively small number of patients treated with Pergonal. Treatment with gonadotrophic hormones, especially Pergonal 500, seems to be indicated in cases of oligoasthenospermia, hypogonadotrophic hypogonadism (or secondary hypogonadism) and at least a short-dated correction of the spermiogram to normal can be expected in approximately one fourth of cases. A long-term testosterone (Agovirin) administration has a beneficial effect on the qualitative aspect of the treatment in that it enhances sperm motility.