BACKGROUND: The provision of specialist non-transplant hepatobiliary services in the UK is fragmented and there is little consensus on the manpower and resource requirements to meet the needs of defined populations. METHODS: We report our experience with a hepatobiliary service established 5 years ago in Sheffield to provide a tertiary referral service to the population of the North Trent health area and attempt to provide estimates of resource requirements based on patterns of current use. RESULTS: A total of 615 patients with hepatobiliary conditions requiring specialist treatment were referred to the service during 1997-2002. The majority of patients (69%) were referred for consideration of liver resection for colorectal liver metastases. In all, 251 resections were performed in 240 (39% of all referred) patients. The current operation rates for colorectal metastases are about 4 per 100,000 population per year and for other complex hepatobiliary procedures are also 4 per 100,000 population per year giving a total "need" of 8 procedures per 100,000 population per year. For the current population in England and Wales, this would mean 25 specialist hepatobiliary centres performing in total approximately 2000 hepatic resections for colorectal cancer metastases and 2000 other tertiary hepatobiliary procedures each year. CONCLUSIONS: Our experience supports the model of centralisation of non-transplant hepatobiliary surgical services and indicates the extent of hitherto unmet demand in our geographical area. We estimate that a minimum of two full-time specialist hepatobiliary surgeons with appropriate ancillary support are required for a typical population of 2 million people in the UK.