Background Research involving the public as partners often proves difficult to locate due to the variations in terms used to describe public involvement, and inability of medical databases to index this concept effectively. Objective To design a search filter to identify literature where patient and public involvement (PPI) was used in health research. Methods A reference standard of 172 PPI papers was formed. The references were divided into a development set and a test set. Search terms were identified from common words, phrases and synonyms in the development set. These terms were combined as a search strategy for medline via OvidSP, which was then tested for sensitivity against the test set. The resultant search filter was then assessed for sensitivity, specificity and precision using a previously published systematic review. Results The search filter was found to be highly sensitive 98.5% in initial testing. When tested against results generated by a ‘real‐life’ systematic review, the filter had a specificity of 81%. However, sensitivity dropped to 58%. Adjustments to the population group of terms increased the sensitivity to 73%. Conclusion The PPI filter designed for medline via OvidSP could aid information specialists and researchers trying to find literature specific to PPI.