Background: In some patients with colorectal liver metastases it is not clear whether liver resection or isolated liver perfusion is the best treatment option. For instance, the risk of complications after surgery may be so substantial and affect subsequent survival. Aim of the present study is to compare complication occurrence and its effect on survival after liver resection and perfusion. Methods: Patient records of all 225 patients with colorectal liver metastases treated with liver resection (n = 121) or liver perfusion (n = 104) in the period 1997-2006 were reviewed for complications during the initial hospitalisation until 30 d after discharge, and to assess patient survival until the last hospital visit. Median duration of follow-up was 38 mo for overall survival and 22 mo for survival after surgery. Results: Complications occurred less often in patients undergoing resection than perfusion (29.8% versus 49.0%, X² = 8.77, P < 0.01). Postoperative mortality rates were similar in both groups (4.1% and 4.8%, respectively). As expected, long term survival after liver surgery was better in the resection group: at 3 y, 60% of patients survived in the resection group, compared with 22% after liver perfusion (log rank X² = 35.29 P < 0.001). However, liver resection patients with postoperative complications, had similar survival as perfusion patients without complications (log rank X² = 2.45, p = 0.12). This remained after adjustment for differences between the patient groups at time of surgery. Conclusion: Liver resection has superior long-term survival, but survival is significantly reduced by the occurrence of post-surgical complications. When complications occur after liver resection, survival is comparable to patients who underwent uncomplicated liver perfusion.