Ovarian cancer (OC) poses significant treatment challenges due to late-stage diagnosis and a complex tumor microenvironment contributing to therapy resistance. We optimized a U-CUP perfusion-based bioreactor method to culture patient-derived primary and metastatic OC specimens, demonstrating that perfusion better preserves cancer cell viability and proliferation, both when fresh and slow-frozen tissues were used. Perfused cultures maintained key microenvironment components, including cancer-associated fibroblasts, endothelial and immune cells. Genetic analysis confirmed the retention in culture of tumor-specific driver mutations. We hence challenged ad hoc generated cisplatin-sensitive and resistant OC cells with cisplatin during growth in U-CUP, validating our system for the testing of drug response. Finally, treatment of slow-frozen OC tissues with carboplatin/paclitaxel revealed different degrees of response to treatment, as indicated by variations in tumor necrosis and number of residual PAX8 cells, providing the bases for the prompt evaluation of OC standard chemotherapy efficacy in our ex vivo system.