Practicing physicians know that patients frequently ask for a variety of clinical services that may or may not be clinically indicated. However, the nature and prevalence of such requests has not been ascertained by direct observation. In this study, Kravitz and colleagues audiotaped 559 visits to 45 internists, cardiologists, and family physicians. About one fourth of patients requested at least 1 diagnostic test, specialty referral, or new prescription medication. Such requests were more common among patients experiencing greater health-related distress (P<.05) and much more common among patients of internists and family physicians than among patients of cardiologists (P<.01). Compared with patients making no requests, patients making requests for referrals and prescription drugs were much more likely to receive them. The authors conclude that patients' requests for clinical services are both pervasive and influential.