After discussing the frequency of bilateral testicular tumours, attention is drawn to their rising incidence. In the 10 year period 1967 to 1976, three patients with bilateral testicular tumour were treated at the Department of Urology of the University Medical School of Pécs. Two had successively appearing bilateral seminoma and embryonal carcinoma, in the third patient simultaneously a malignant lymphoma appeared. As regards the question whether bilateral testicular tumours are two independent primary tumours or one is a metastastatic growth, presence of two primary tumours is assumed. The special features of therapy and prognosis are discussed.