Between 1978 and 1985, 128 patients with germinal tumors of the testes were treated at the Val-de-Grâce Hospital; biological market levels--beta HCG and AFP--were determined before and after orchidectomy in the peripheral blood and during orchidectomy in testicular blood in 76 patients. HCG levels were elevated in 13% of seminomas and HCG and/or AFP levels were elevated in 76% of non seminomas; the sensitivity of the determination was greater in testicular blood. However, in our study, there was no parallelism between marker levels before orchidectomy and tumor stage or prognosis. The change in HCG and/or AFP levels appears to an index of the response to therapy: 4 patients with high HCG and/or AFP levels during chemotherapy died. The diagnosis of recurrence is not always documented by elevated marker levels and monitoring must always documented by elevated marker levels and monitoring must always include both determination of marker levels and imaging.