OBJECTIVES: Women with advanced-stage, low-grade serous ovarian carcinoma (LGSC) have low chemotherapy response rates and poor overall survival. Most LGSC tumors overexpress hormone receptors, which represent a potential treatment target. Our study objective was to determine the outcomes of patients with advanced-stage LGSC treated with primary cytoreductive surgery (CRS) and hormone therapy (HT). METHODS: A retrospective study was performed at two academic cancer centers. Patients with Stage II-IV LGSC underwent either primary or interval CRS followed by adjuvant HT between 2004 and 2016. Gynecologic pathologists reviewed all cases. Two-year progression-free (PFS) and overall survival (OS) were calculated. RESULTS: Twenty-seven patients were studied; primary CRS followed by HT were administered in 26, while 1 patient had neoadjuvant chemotherapy followed by CRS and HT. The median patient age was 47.5, and patients had Stage II (n=2), Stage IIIA (n=6), Stage IIIC (n=18), and Stage IV (n=1) disease. Optimal cytoreduction to no gross residual was achieved in 85.2%. Ninety six percent of tumors expressed estrogen receptors, while only 32% expressed progesterone receptors. Letrozole was administered post operatively in 55.5% cases, anastrozole in 37.1% and tamoxifen in 7.4%. After a median follow up of 41months, only 6 patients (22.2%) have developed a tumor recurrence and two patients have died of disease. Median PFS and OS have not yet been reached, but 2-year PFS and OS were 82.8% and 96.3%, respectively, and 3-year PFS and OS were 79.0% and 92.6%, respectively. CONCLUSIONS: Our series describes the initial experience with cytoreductive surgery and hormonal monotherapy for women with Stage II-IV primary ovarian LGSC. While surgery remains the mainstay of treatment, chemotherapy may not be necessary in patients with advanced-stage disease who receive adjuvant hormonal therapy. A cooperative group, Phase III trial is planned to define the optimal therapy for women with this ovarian carcinoma subtype.