The current role of tumor markers in the management of ovarian cancer is reviewed. The most useful tumor marker in epithelial ovarian cancer is still the antigen CA125. However, the level of this marker is modified by peritoneal irritation from endometriosis or inflammatory disease. Furthermore, the level is not elevated in nearly half of patients with the stage I disease, suggesting a limited value as a screening marker. In CA125 positive cases, the marker determination is a sensitive indicator in the early diagnosis of progressive disease in ovarian cancer. The lack of an effective second-line regimen, however, limits the value of the antigen as monitoring marker. Expectations for the new tumor markers lysophosphatidic acid and inhibin are also briefly discussed.