Ninety-three cases of germinal testicular tumors with urinary gonadotropin (HCG) values, estimated by biologic or radioimmunoassay techniques, were reviewed. Preoperative values of HCG and subsequent postoperative values were related to response to treatment and prognosis. Twenty-five patients (26.9 per cent) comprised the seminoma group, and 68 patients (73.1 per cent) the nonseminomatous groups of germinal neoplasms. High HCG values were observed in the nonseminomatous group pre- and postoperatively by both assay procedures. Most significant was the high HCG values postoperatively (p smaller than 0.05, x2 equals 5.21 and p smaller than 0.05, x2 equals 5.23) for the biologic assay and radioimmunoassay, respectively, with high HCG values being associated with a poor cumulative 24 per cent two-year survival rate. Urinary HCG assay is of prognostic value in the ongoing management of testicular neoplasms. In the future, serum HCG assays may be of additional benefit.