Background: Organisations need to systematically identify contributory factors (or causes) which impact on patient safety in order to effectively learn from error. Investigations of error have tended to focus on taking a reactive approach to learning from error, mainly relying on incident-reporting systems. Existing frameworks which aim to identify latent causes of error rely almost exclusively on evidence from non-healthcare settings. In view of this, the Yorkshire Contributory Factors Framework (YCFF) was developed in the hospital setting. Eighty-five percent of healthcare contacts occur in primary care. As a result, this review will build on the work that produced the YCFF, by examining the empirical evidence that relates to the contributory factors of error within a primary care setting. Methods/design: Four electronic bibliographic databases will be searched: MEDLINE, Embase, PsycInfo and CINAHL. The database search will be supplemented by additional search methodologies including citation searching and snowballing strategies which include reviewing reference lists and reviewing relevant journal table of contents, that is, BMJ Quality and Safety. Our search strategy will include search combinations of three key blocks of terms. Studies will not be excluded based on design. Included studies will be empirical studies conducted in a primary care setting. They will include some description of the factors that contribute to patient safety. One reviewer (SG) will screen all the titles and abstracts, whilst a second reviewer will screen 50% of the abstracts. Two reviewers (SG and AH) will perform study selection, quality assessment and data extraction using standard forms. Disagreements will be resolved through discussion or third party adjudication. Data to be collected include study characteristics (year, objective, research method, setting, country), participant characteristics (number, age, gender, diagnoses), patient safety incident type and characteristics, practice characteristics and study outcomes. Discussion: The review will summarise the literature relating to contributory factors to patient safety incidents in primary care. The findings from this review will provide an evidence-based contributory factors framework for use in the primary care setting. It will increase understanding of factors that contribute to patient safety incidents and ultimately improve quality of health care.