OBJECTIVES: Outcome of ovarian cancer is better when surgery is provided by a gynaecological oncologist than by a general gynaecologist. However, when all patients with an adnexal mass have to be operated by gynaecological oncologists, this requires a change in the organisation of care, which generates additional costs. In this study, we assess the costs and effects of centralised and regular care for women with an ovarian malignancy in the Netherlands. METHODS: We performed a cost-effectiveness analysis. We considered three strategies. In the first strategy, patients were operated by a general gynaecologist (general care strategy). In the second strategy, patients were operated by a gynaecological oncologist (specialised care strategy). In the third strategy, evaluation of the adnexal mass took place prior to surgery by means of the Risk of Malignancy Index (diagnostic strategy). Patients at high risk for malignancy were supposed to be operated in a specialised care setting, whereas low risk patients were supposed to be operated in a general care setting. For each strategy we calculated life expectancy and incremental costs per life year gained (LYG). RESULTS: Mean life expectancy of a patient with an ovarian malignancy in the general strategy was 2.7 years, in the diagnostic strategy 3.0 years and in the specialised strategy 3.1 years. The incremental costs to gain one additional life year with specialised surgery as compared to the diagnostic strategy were € 61,871 per LYG. CONCLUSION: In women with an adnexal mass, a diagnostic strategy prior to the decision for surgery by a general gynaecologist or a gynaecological oncologist provides the best balance between costs and effects.