Objective. Ovarian cancer is the fourth most common cancer and the eighth leading cause of death due to cancer in women. People affected by ovarian cancer often experience relapses, and then need to be treated with various lines of treatment. The study aim was the effectiveness of letrozole in patients with relapsed advanced ovarian cancer already subjected to multiple lines of treatment (≥3) and chemotherapy was no longer the option of choice. The main outcome of our study was to evaluate Patients-Free-Survival (PFS). The secondary outcomes were the assessment of Overall Survival(OS), Treatment Free Interval(TFI), Quality-of-life(QoL) and treatment-related toxicities.Materials and Methods. This is a case-control retrospective observational study. The patients who were included in the group of cases were those who took 1 tablet of Letrozole 2.5mg/day. The QoL was analyzed in terms of symptomatology, using the EORTC QLQ-C30 and QLQ-O28Results. 40 patients were included: 20 were treated with Letrozole and 20 as controls. The average PFS in the treated group was similar to the control group (3.8vs2.7 months,p=0.39). The average OS in the treated group was superior to the control group (75vs48.6 months,p=0.07). The average TFI was significantly higher in the treated group than in the controls (10.3vs3.8 months,p=0.008). Analysis of the symptoms reported that were much more present in the control group than in the letrozole group. Conclusions.Letrozole is associated with good PFS and increased OS in patients for which other chemotherapeutic options are no longer eligible. Other studies are needed to validate these preliminary results.