Aim: The aims of this study were to explore clinical outcomes and assess the learning curve for cytoreductive surgery and perioperative intraperitoneal chemotherapy (PIC) for patients with a high peritoneal cancer index (PCI). Patients and Methods: This was a retrospective study of patients with a PCI of 20 or more following CRS and PIC. Outcomes in five successive groups based on the operation date were analyzed. Results: Three hundred and five patients were included in the study. The median overall survival (OS) was 89.3 months (95% confidence interval=58.9-107.6 months). OS at 1, 3 and 5 years of our study cohort was 89.4%, 70.4% and 57.5%, respectively. In terms of the learning curve, the mean duration of operation and hospital mortality decreased (p<0.001 and p=0.006 respectively). A trend for decreasing intensive care unit stay (p=0.497), high dependency unit stay (p=0.042) and total hospital stay (p=0.202) were also recorded. Conclusion: A high PCI alone should not be a contraindication for cytoreductive surgery and PIC in specialized centres.