The management of ovarian germ cell tumours (GCTs) has changed dramatically over the last 15 years. The combination of the introduction of tumour markers which accurately monitor the behaviour of the majority of germ cell tumours together with the introduction of newer chemotherapeutic agents has meant that few patients even with metastases should succumb from their disease. The tumour markers, human chorionic gonadotrophin (hCG) and alpha-foetoprotein (AFP) and, to a lesser extent, lactate dehydrogenase (LDH) and placental alkaline phosphatase (PLAP) are routinely used in assisting diagnosis, monitoring response to treatment and increasing the sensitivity of follow-up of patients after completing treatment. Analysis of our last 51 patients with all cell types of ovarian germ cell tumour has confirmed the importance of both hCG and AFP in that 45 (88%) of 51 patients had either or both of these tumour markers raised at the start of treatment for metastatic disease. Our data on LDH is incomplete since this has not been a routine assay until 1984 and, of the patients with active disease 10 (48%) had raised LDH at the start of treatment. PLAP has also been measured in a number of patients both on active treatment and in remission. 11 (50%) had raised levels of PLAP at the start of treatment but there was also a false positive rate of 8 (24%) of the 33 patients who were in remission and had not subsequently relapsed.