Hepatic C virus (HCV) has been recognized increasingly as a major public health crisis in the United States, causing infection in an estimated 3.5 million people and resulting in 8000 to 10,000 deaths annually from liver-related complications. This article focuses on the clinical aspects and diagnosis of hepatitis C, the importance of excluding other chronic liver diseases, and the current basis and strategy for treatment of HCV infection with interferon. Ideally, it will help primary care providers with the task of evaluating, diagnosing, teaching, and caring for patients with this chronic, potentially debilitating, and lethal disease.