BACKGROUND: The present study is the result of an internal audit and examines the profiles of complainants and the sources and nature of complaints toward the staff in a tertiary care pain clinic, the Comprehensive Pain Program of the Toronto Western Hospital in Toronto, Ontario.METHODS: All sources of complaints over a nine-year period were reviewed, which included the following: Toronto Western Hospital Patient Relations (PR) records, with a subset of the files qualitatively analyzed in depth regarding the nature of complaints and complainants; complaints that bypassed PR and were addressed directly to the program director against members of the staff; complaints to the College of Physicians and Surgeons of Ontario; and complaints recorded anonymously at rateMDs.com.RESULTS: Although the prevalence of PR complaints was very low (1.73 complaints per 1000 visits), several other sources of complaints were identified. The typical complainant was a Canadian-born woman acting on her behalf or on behalf of a family member. More than one-half of the complaints were directed against the physicians regarding their opinion of psychological factors augmenting the patient’s presentation and/or inappropriate use of opioids. Defensive techniques instituted by the Comprehensive Pain Program staff in reaction to the complaints are discussed, and pertinent literature is reviewed.CONCLUSION: The present study is the first to examine the nature of complaints and complainants from a Canadian pain clinic. Further studies are needed to explore the complex issues of patient and staff interactions, and complaints in the era of ‘patient-centred care’.