The therapeutic success of treatment of testicular maldescent must be judged according to 2 parameters, - I. occurrence of descent, II. fertility. Ad I. Indication for hCG-treatment is always given unless an unequivocal indication for operation exists, i.e. ectopias, accompanying hernias, retention after herniotomy and advanced puberty. The optimal time for treatment is the second year of life. The large European statistics which include the prescrotal but not the retractile testes, unanimously show success rates of 50-55%. In the largest American series which does not include prescrotal testicles, descent was observed in 40% of the bilateral and in 30% of the unilateral cases. Analyzing those cases which did not respond to hormones but had to be operated, in the majority of cases ectopic, not dystopic gonads were found. Ad II. Infertility in testicular maldescent can have two reasons, 1. congenital anomalies of the primordium, 2. acquired damages due to the malposition. The few large prospective studies at hand show fertility in the majority of cases with descent after hCG, but in the minority of those coming down only after additional operation. Obviously the latter group represents a negative selection. Unilateral cases had a higher fertility rate than bilateral ones.