Objectives: The study aimed (a) to test a method of identifying patients who have been repeatedly referred (RR) from primary care to medical outpatient clinics where they have received multiple diagnoses of medically unexplained symptoms (MUS) and (b) to describe the prevalence and characteristics of these patients. Methods: RR patients with MUS (RRMUS) were arbitrarily defined as those with (a) five or more referrals in a 5-year period and (b) a specialist final diagnosis of MUS for at least three of these referrals. A two-stage method of identifying these patients was piloted in one primary care practice: Stage I used computerized health service data to identify RR; Stage 2 used manual case note review to identify referrals that ended with specialist diagnoses of MUS. The RRMUS patients identified were asked to complete a questionnaire, a psychiatric diagnostic interview, and their GPs were asked to rate how "difficult to manage" they were. Results: The process was feasible and reasonably accurate. From 6770 registered patients aged 18 to 65 years, 23 (0.3%) were identified as RRMUS. They accounted for 157 referrals over the 5-year period. Sixteen agreed to further assessment, and 8 (50%) had a current anxiety or depressive disorder. GPs rated only 8 (50%) as "difficult to manage." Conclusion: This two-stage procedure offers a practical method of identifying RRMUS patients in primary care as a first step in achieving more cost-effective care. These patients have substantial psychiatric morbidity. (C) 2009 Elsevier Inc. All rights reserved.