h i g h l i g h t s Combined treatment for peritoneal and liver metastases from colon cancer was evaluated. Toxicity to preoperative chemotherapy and size of LM were poor prognostic factors. These criteria could help in better selecting patients for such extensive surgery. a b s t r a c t Purpose: Selection of patients for resection of synchronous liver metastases (LM) and peritoneal carci-nomatosis (PC) of colorectal cancer (CRC) remains a debated issue since morbidity of this surgery is not negligible. We aimed to define overall survival (OS) prognostic criteria in patients undergoing PC surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) and LM resection. Methods: This monocentric and comparative study included all consecutive patients operated for LM (LM group, n ¼ 77), PC (HIPEC group, n ¼ 18) and PC þ LM (LM þ HIPEC group, n ¼ 9) from January 2007 to May 2011. Characteristics of the 3 groups were prospectively collected and retrospectively compared. Results: Median follow-up was 56,5 months. Major morbidity and mortality were respectively 14% and 3%. Two-year disease free and overall survival rates were respectively 23% and 76%. There were significantly more Dindo grade III-IV complications in LM þ HIPEC group. In multivariate analysis, grade II and III preoperative chemotherapy-induced toxicity and size of LM were identified as poor OS prognostic factors whereas response to preoperative chemotherapy significantly increases OS. OS was not different (p ¼ 0.235) between the 3 groups. Conclusion: Toxicity to preoperative chemotherapy and size of LM were identified as poor prognostic factors in patients undergoing simultaneous PC and LM surgery. These criteria could help in better selecting patients for such extensive surgery.