Objective: The therapeutic effect of PARP inhibitors (PARPi) monotherapy compared with platinum-based chemotherapy, and the impact to subsequent platinum-based chemotherapy after PARPi resistance were inconclusive. Design: Retrospective cohort study. Setting: Patients from seven medical centers in China. Population: BRCA1/2-mutated ovarian cancer patients with secondary platinum-sensitive relapse, without any maintenance regimen after first- and second-line platinum therapy, and the secondary platinum-free interval (PFI) was more than 6 months. Methods: Patients in study group (n=31) were treated with PARPi monotherapy until disease progression, and patients in control group (n=33) were treated with platinum-based chemotherapy without restriction. Main Outcome Measures: RECIST and GCIG standard, Kaplan-Meier plotter Results: The objective response rate (ORR: 77.4% vs. 84.0%, p=0.538) and median progression-free survival (mPFS: 8.6 vs. 11.1 months, p=0.679) were comparable. PARPi monotherapy significantly prolonged post-recurrent survival (PRS, HR=0.35, p=0.024), and was the independent factor associated with PRS (HR=0.33, p=0.038). The median time from treatment to first subsequent therapy or death (TFST) of patients with platinum-based chemotherapy after PARPi progression and patients in control group with PFI≥6months after third-line platinum-based chemotherapy was comparable (mTFST: 7.5 vs. 7.1 months, p=0.800). Further survival analysis showed that PRS of patients with PARPi monotherapy were similar to patients with PFI≥6 months after third-line platinum chemotherapy (HR=0.66, p=0.503), and superior to patients with PFI<6 months after third-line platinum chemotherapy (HR=0.15, p=0.009). Conclusions: PARPi monotherapy was equivalent to platinum-based chemotherapy for BRCA1/2-mutated ovarian cancer patients with secondary platinum-sensitive recurrence, and could improve prognosis.