Background: This study was to assess the risk of venous thromboembolism (VTE) in patients with peritoneal carcinomatosis (PC) and to evaluate the safety and feasibility of physiotherapy program to prevent VTE during cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Methods: For VTE prevention, we developed a systematic physiotherapy program consisting of active exercises of both arms and legs, and intermittent pneumatic compression device to massage both legs. This physiotherapy was applied to all patients, and the VTE-related events were recorded and analyzed. Results: Cytoreductive surgery + HIPEC was performed on 466 patients with PC. All patients had highest VTE risk, with the median Caprini risk factor score being 11. During the 3-month observation period, 8 patients had 9 (1.9%) clinically symptomatic VTE events, including 8 (1.7%) deep vein thrombosis and 1 (0.2%) pulmonary embolism. Among those, 5 patients received pharmacological treatments with low-molecular-weight heparin, and the other 3 received physical exercises only. All these patients recovered well, and there was no mortality about VTE perioperatively. Conclusions: Patients with PC treated by CRS + HIPEC are at highest risk for VTE. The systematic physiotherapy program is safe and feasible to prevent VTE post CRS + HIPEC.