Background: Despite the widespread use of surgical resection as a treatment for hepatic colorectal metastases, the value of resecting more than three metastases remains controversial. It was the objective of this study to determine if resection of larger numbers of metastases affects patient survival.Method: The survival of 123 consecutive patients who underwent curative hepatic resection for colorectal metastases between 1989 and 1999 by a single surgeon was analysed retrospectively. Kaplan-Meier survival statistics and Cox regression were used to determine the factors that affected survival, and logistic regression was used to determine the factors that affected the risk of recurrence of hepatic disease.Results: The median survival rate for the whole group of patients was 38 months, with 1, 3 and 5 year survival rates of 88%, 53% and 31% respectively. The survival rate of patients undergoing resection of four to seven metastases (n = 22; 5 year survival = 39%) was not significantly different to that of patients undergoing resection of one to three metastases (n = 91; 5 year survival 30%), P = 0.9. Age, sex, primary cancer site, hepatic disease distribution, resection margins and adjuvant hepatic arterial chemotherapy (HAC) did not affect survival. Local invasion of the hepatic metastases (relative risk (RR) = 2.9; P = 0.001) and hepatic disease recurrence (RR = 2.1; P = 0.007) were the only factors that independently affected survival. Local invasion of the hepatic metastasis was the only factor associated with an increased risk of hepatic recurrence (RR = 2.8; P = 0.03). Adjuvant HAC did not affect the risk of hepatic recurrence (RR = 1.5, P = 0.4).Conclusion: Although there are no randomized trials that quantify any survival benefit from resection of liver metastases, the comparison of our results with well documented historical evidence indicates that surgical resection of up to seven colorectal liver metastases can result in a significant survival benefit.