The authors investigated the prevalence of multiple medically unexplained symptoms (MMUS) as identified by primary care physicians (PCPs) in a systematic sample of 172 patients. Patients were from a university-affiliated urban primary care practice serving a low-income population. Patients with a history of MMUS were older (mean: 57.2 vs. 53.0 years), more likely to be female (90.5% vs. 72.3%), and less likely to be married or living with a partner (14.4% vs. 36.2%) than those without MMUS. Patients with MMUS had over twice the rate of any current psychiatric disorder, almost two-and-a-half times the rate of any current anxiety disorder, and greater functional impairment. These data suggest that patients with MMUS are as common in urban primary care clinics as in more affluent clinics and reinforce the need for PCPs to screen these patients for common and treatable psychiatric conditions.