We have reviewed 77 patients with Non-seminomatous germ cell tumour of the testis (NSGCTT) treated at a single institution. A residual mass following definitive treatment occurred in 16 patients (35%), 13 of whom had a resection of the mass, yielding active tumour in only one patient. Nine patients (12%) relapsed including four of the 14 with Stage I disease who were treated by orchidectomy alone. Four relapses occurred at more than two and a half years after primary treatment. Relapse prior to the development of clinical symptoms or signs was evident in three of nine patients; in two patients by routine imaging and one with elevated routine serum markers. Three of the nine patients who relapsed had elevated serum markers. Two patients died from disease but there were four treatment-related deaths (7%). Overall, 64 patients (83%) remain disease free at the time of follow-up. A further seven (9%) have been lost to follow-up but were disease-free at a minimum of 26 months after diagnosis. This study confirms features of this disease including the excellent prognosis when adequately treated. However, it also reveals the problems of late or marker negative relapses, the implementation of an observation policy in Stage I disease and treatment related mortality in young men.