Neuron-specific enolase was determined in 100 patients with germ-cell tumors. An elevation was found in 5/18 patients with advanced seminoma and in 7/25 patients with advanced nonseminoma. Including all tumor stages of both seminoma and nonseminoma, we found less than 20% NSE-positive patients. Some of these showed false-positive or false-negative results during follow-up examinations. NSE does not seem to be a valuable tumor marker in germ-cell tumors.