Abstract Background In some patients undergoing right hepatic trisectionectomy for metastases, extension of the resection beyond the falciform ligament is necessary to achieve tumour clearance. The aim of the present study was to assess the early and long-term outcomes and hepatic function in patients who underwent extensive liver resection beyond right trisectionectomy. Methods Thirty-eight patients who had extension of a right trisectionectomy, either in contiguity (IC) or in a non-anatomical (NA) fashion, for liver metastases were included in the study. In-hospital mortality, hepatic function and other morbidity were recorded. Survival outcomes were analysed for the subgroup of patients with colorectal liver metastases. The clinical risk score described by the Memorial Sloan–Kettering Cancer Center was applied to all patients with colorectal liver metastases. Results Sixteen patients had IC resection, 15 NA resection, and seven had both IC and NA procedures. There was one in-hospital death. Hepatic dysfunction was seen in 25 patients and two developed liver failure. Disease-free actuarial 3-year survival was 42 per cent for patients with colorectal liver metastases. Survival was significantly better in patients with a clinical risk score of 3 or less. Conclusion Extension of right trisectionectomy for liver metastases was associated with a low risk of death and hepatic failure.