Background: Combined therapy involving cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy has been shown to improve survival outcomes for patients with diffuse malignant peritoneal mesothelioma (DMPM). The present study aims to investigate gender as a potential prognostic factor on overall survival. Patients and methods: Over a period of two decades, 294 patients who underwent CRS and perioperative intraperitoneal chemotherapy were selected from a large multi-institutional registry to assess the prognostic significance of gender on overall survival. Results: Female patients were shown to have a significantly improved survival outcome than male patients (P < 0.001). Staging according to a recently proposed tumor-node-metastasis categorization system was significant in both genders. Older female patients had significantly worse survival than younger female patients (P = 0.019), a finding that was absent in male patients. Female patients with low-stage disease were found to have a very favorable long-term outcome after combined treatment. Conclusions: Gender has demonstrated a significant impact on overall survival for patients with DMPM after CRS and perioperative intraperitoneal chemotherapy. An improved understanding of the role of estrogen in the pathogenesis of DMPM may improve the prognostication of patients and determine the role of adjuvant hormonal treatment in the future.