The original prognostic model in non-seminomatous germ cell tumours of the testis at the Institut Gustave-Roussy was updated in a larger patient population. As in the former model human chorionic gonadotrophin (hCG) and alpha-feto-protein (AFP) serum concentrations attained prognostic significance in the multivariate analysis. We studied two important issues in this patient population: the impact of expressing hCG values in mass units and of the introduction of etoposide-containing chemotherapy. Etoposide has a major impact on the determination of the prognostic group limits which are considerably increased. It is, thus, suggested to reevaluate prognostic models in patient populations treated by modern chemotherapy regimens.