Introduction Primary care trusts (PCTs) in England are required to set in place local arrangements to identify and deal with concerns about general practitioners' (GPs') performance. Assessing GP performance at a local level can be challenging and there is little published information available to describe the methods PCTs use. This paper describes the local assessment methods developed by two PCTs. Methods Gateshead and South Tyneside PCTs have jointly developed methods to locally assess whether GPs are underperforming. The methods involve lay, clinical and management representatives and employ a variety of tools including case-based assessment and a questionnaire to colleagues. Most of these tools measure performance against the standards set out in Good Medical Practice or collate data derived from nationally validated surveys. The methods have been developed to promote transparency, objectivity and consistency while making the most of scarce local expertise. Results In our experience, case-based assessment and questionnaires to colleagues provide the most helpful information. Our local assessments enable practitioners to continue their work and do not incur travel or accommodation costs for the assessed or the assessors. GPs and their defence organisations find the methods acceptable. Conclusions It would be helpful for other PCTs to publicise their assessment methods so that best practice can be developed and standardised, thus ensuring that all patients and GPs receive the same levels of protection and support at a local level.