['Carcinomatosis of colorectal origin is increasingly treated by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CS-HIPEC). This procedure commonly involves multivisceral resection (MVR) with potentially high morbidity. We analyzed the effect of MVR on the outcome after CS-HIPEC.', 'All patients with colorectal carcinomatosis operated between June 2001 and June 2007 were included. MVR was defined as resection of two or more organs (n = 35). Patients without any or with a single visceral resection formed a control group (n = 30).', 'Sixty-five patients underwent 72 procedures. MVR was not strongly associated with the mortality, morbidity, reoperation, or readmission. Morbidity, but not mortality, was more common in patients requiring bowel anastomosis (36 of 51 vs. 7 of 21, P = .003). Median survival from the diagnosis of carcinomatosis was not significantly different between the MVR and controls (32.8 months vs. 20.0 months, P = .787). Similarly, the median survival from the time of cytoreduction was not significantly different (20.2 vs. 14.3 months; P = .436). Independent predictors of survival in the Cox regression model were presence of residual disease >5 mm (hazard ratio = 4.5, P = .048), evidence of carcinomatosis on preoperative computed tomographic scan (6.1, P = .008), and initial diagnosis of cancer as systemic (2.6, P = .049). MVR had no statistically significant effect on survival (.441, P = .133).'] Does multivisceral resection affect morbidity and survival after cytoreductive surgery and chemoperfusion for carcinomatosis from colorectal cancer?