Data from the 1997 and 1998 National Ambulatory Medical Care Surveys were analyzed to describe nationally representative patterns of office-based ambulatory medical care for work-related injuries and illnesses. Key dimensions of care included patient demographics, diagnoses, utilization of services, provider and payer information, and characteristics of the clinical setting in which care was delivered. Multivariate analyses revealed that compared to visits for nonwork related conditions, ambulatory care visits for work-related conditions are more likely to involve x-rays, injury prevention counseling, and physiotherapy. Surgical procedures, mental health counseling, prescription drug medication, and the taking of blood pressure were found to be relatively less common. Additionally, authorization for care was required considerably more often at visits for work-related conditions, and the provider for patients with work-related conditions was less likely to be the patient's regular primary care physician.