OBJECTIVE: The aim of this prospective study was to analyze the impact of second-look surgery in an attempt to treat peritoneal carcinomatosis (PC) at an early stage in a series of patients at high risk of developing PC from colorectal cancer. BACKGROUND: The prognosis of colorectal PC has recently been improved with hyperthermic intraperitoneal chemotherapy (HIPEC) after complete cytoreductive surgery (CCRS), and could be further improved if PC could be treated at an early stage. But, currently, the diagnosis of early PC is not accessible to imaging. PATIENTS AND METHODS: From 1999 to 2006, 29 patients without any sign of recurrence on imaging studies underwent second-look surgery 13 months after resection of the primary tumor. Patients were selected according to primary tumor-associated criteria: resected minimal synchronous macroscopic PC (n = 16), synchronous ovarian metastases (n = 4), perforated primary tumor (n = 9). RESULTS: PC was found and treated with CCRS plus HIPEC in 16 of 29 (55%) cases, corresponding to 10 of 16 patients with initial PC, 3 of 4 patients with synchronous ovarian metastases and 3 of 9 patients with a perforated primary tumor. There was no postoperative mortality, and morbidity (grade III/IV) occurred in 14% of cases. After a median follow-up of 27 months (range, 6-96), 8 of 16 patients treated with CCRS and HIPEC are free of disease, 4 relapsed in the peritoneum, and 4 developed isolated visceral metastases. CONCLUSION: Performing second-look surgery at 1 year in selected patients at high risk of developing PC allowed the early detection and treatment of PC in 55% of cases. Our preliminary results have encouraged us to pursue this strategy and to evaluate it in a prospective multicenter trial.