Between 1980 and 1989, 138 patients with stage I carcinoma of the testes were treated and followed up; 81 patients had seminoma and 57 had non-seminomatous tumours. Between January 1980 and December 1983, patients with seminoma were treated by orchiectomy, followed by complementary radiotherapy to aortic and ipsilateral pelvic nodes. Retroperitoneal lymph node dissection (RPLND) was performed in patients with non-seminomatous tumours. After January 1984 the treatment strategy was changed and orchiectomy was followed by a surveillance policy in all histological types. In seminoma patients, 1 of 36 patients (3%) treated with complementary radiotherapy and 5 of 45 (11%) on the surveillance policy relapsed. All achieved a complete response after chemotherapy. In non-seminomatous tumours, 3 of 21 patients (14%) treated with complementary lymphadenectomy relapsed, in contrast to 11 of 36 (31%) surveillance policy patients. All patients who relapsed obtained a complete response with chemotherapy. All patients are currently free of disease. There were no differences in survival between both treatment policies. We conclude that a wait and see policy in stage I testicular tumours is feasible and provides the same results as more interventionist practices.