Purpose Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is an established treatment for peritoneal malignancy. A hypercoagulable state in these patients and the associated risk of venous thromboembolism (VTE), remains the commonest cause of 30-day mortality. This study aimed to evaluate the prevalence and perioperative factors associated with baseline hypercoagulability detected by Rotational thromboelastometry (ROTEM), a point-of-care haemostatic assay, in peritoneal malignancy patients. Methodology A retrospective cohort study was performed in a peritoneal malignancy unit on patients undergoing CRS 2019-2023, who underwent baseline ROTEM testing. Patients were divided into Group A (hypercoagulable) and Group B (normal coagulation). Baseline characteristics, pathology results, operative details and post operative outcomes were reviewed. Univariate and multivariate analysis were used to identify factors associated with baseline hypercoagulability. Results 70 patients were included, 23 patients in Group A (32.9%) and 47 patients in Group B (67.1%). Group A had a lower preoperative haemoglobin (p<0.001), higher platelet count (p=0.001) and a significantly higher median peritoneal carcinomatosis index (33 vs 10, p=0.003). Appendiceal primary was associated with hypercoagulability (47.8% vs 23.4%, p=0.039). Although Group A had a higher incidence of VTE events (30.4% vs 23.4%) this was not statistically significant. Conclusions Baseline hypercoagulability exists in one-third of patients with peritoneal malignancy, and was associated with increased tumour burden and primary tumour type. The increasing use of ROTEM is a valuable tool for perioperative management of peritoneal malignancy patients.