BACKGROUND This study evaluated the outcome of liver surgery for colorectal metastases (CLM) in patients over 70 years old in a large international multicentre cohort. METHODS Among 7764 patients who had resection of CLM, 999 (12.9 per cent) were aged 70-75 years, 468 (6.0 per cent) were aged 75-80 years and 157 (2.0 per cent) were at least 80 years old. Elderly patients were compared with the younger population. RESULTS Multinodular and bilateral metastases were less common in elderly than in younger patients (P < 0.001). Preoperative chemotherapy was used less frequently and more limited surgery was performed (P < 0.001). Sixty-day postoperative mortality and morbidity rates were 3.8 and 32.3 per cent respectively, compared with 1.6 and 28.7 per cent in younger patients (both P < 0.001). Three-year overall survival was 57.1 per cent in elderly and 60.2 per cent in younger patients (P < 0.001), and was similar among patients aged 70-75, 75-80 or at least 80 years (57.8, 55.3 and 54.1 per cent respectively; P = 0.160). Independent predictors of survival were more than three metastases, bilateral metastases, concomitant extrahepatic disease and no postoperative chemotherapy. CONCLUSIONS Liver resection for CLM in elderly patients can achieve a reasonable 3-year survival rate, with an acceptable morbidity rate. There should be no upper age limit but risk factors may help predict potential benefit.