The purpose of this phase II trial was to determine the efficacy and safety of the XELOX (capecitabine/oxaliplatin) regimen as first-line therapy in the elderly patients with metastatic colorectal cancer (MCRC). A total of 50 patients with MCRC aged > or = 70 years received oxaliplatin 130 mg m(-2) on day 1 followed by oral capecitabine 1000 mg m(-2) twice daily on days 1-14 every 3 weeks. Patients with creatinine clearance 30-50 ml min(-1) received a reduced dose of capecitabine (750 mg m(-2) twice daily). By intent-to-treat analysis, the overall response rate was 36% (95% CI, 28-49%), with three (6%) complete and 15 (30%) partial responses. In total, 18 patients (36%) had stable disease and 14 (28%) progressed. The median times to disease progression and overall survival were 5.8 months (95% CI, 3.9-7.8 months) and 13.2 months (95% CI, 7.6-16.9 months), respectively. Capecitabine was well tolerated: grade 3/4 adverse events were observed in 14 (28%) patients: 11 (22%) diarrhoea, eight (16%) asthenia, seven (14%) nausea/vomiting, three (6%) neutropenia, three (6%) thrombocytopenia, and two (4%) hand-foot syndrome. There was one treatment-related death from diarrhoea and sepsis. In conclusion, XELOX is well tolerated in elderly patients, with respectable efficacy and a meaningful clinical benefit response. Given its ease of administration compared with combinations of oxaliplatin with 5-FU/LV, it represents a good therapeutic option in the elderly.