601 Background: Increasingly patients with IV stage colorectal cancer received systemic chemotherapy combined with targeted therapy among which bevacizumab. In neoadjuvant situation, a delay of at least 6 weeks between discontinuation of bevacizumab and surgery is recommended, not to increase the risk of complications (delayed healing, bleeding) related to bevacizumab. The goal of this study was to analyze the potential impact of bevacizumab on early morbidity after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with peritoneal carcinomatosis of colorectal origin. Methods: From 2004 to 2010, in three hospitals, 183 patients treated with complete cytoreduction followed by HIPEC for colorectal carcinomatosis, received preoperative treatment. It was either systemic chemotherapy alone (Chemo group, n = 100) or by chemotherapy combined with bevacizumab (Beva group, n = 83). Results: Both patient groups were comparable in the extent of carcinomatosis, assessed on peritoneal cancer index means (10.4 vs 10, p> 0.05), number of resected organs (4.3 vs 3.8, p> 0.05), operative time (420 vs. 380 minutes, p> 0.05) and volume of blood loss (470 vs 510ml, p> 0.05). The median time from discontinuation of bevacizumab and HIPEC was 7 weeks (6-10), always greater than 6 weeks. Nine patients postoperatively died, 4 (4%) in the chemo group and 5 (6%) in the beva group (ns). Grade 3 to 5 complication rate was higher in the beva group (25 vs 12%, p <0.05). Whatever the hospital, complications that may be related to bevacizumab occurred more frequently in patients in the beva group: with more digestive fistulas (18 vs 8%, p <0.05), deep abscesses (13 vs 3 %, p <0.01) and delayed healing (11 vs 2%, p <0.02). Conclusions: Administration of bevacizumab before surgery with complete cytoreduction followed by HIPEC for carcinomatosis colorectal is associated with increased morbidity, probably due to multiple organ resections performed during the surgery. The oncologic benefit of bevacizumab before HIPEC remains to be evaluated.