This study prospectively evaluated 54 patients with ovarian sex cord-stromal tumors (OSCST) to develop diagnostic standards and risk-adapted treatment strategies. Most patients presented with stage IA tumors confined to the ovary and were followed regularly, while some with stage IC or higher received cisplatin-based chemotherapy. After a median follow-up of 59 months, event-free survival was 86% and overall survival was 89%. Prognosis correlated with stage, and chemotherapy seemed effective for advanced-stage tumors. The study provides a standardized approach to classify and treat OSCST.