Many patients in primary care settings have hepatitis. This article discusses signs and symptoms of acute hepatitis and outlines differential diagnoses. The characteristics and methods of transmission of individual hepatotropic viruses, including hepatitis A, B, C, D, E, and G/GB-C are reviewed. Serologic diagnosis of the causative agent is explained. Patient care includes sign and symptom management, medication administration, prevention of transmission to friends and family members, follow-up serologic testing, and evaluation for chronic infection. Preventive measures include vaccination and the use of immune globulin agents for hepatitis A and B. Health care providers should be aware of recent developments in the treatment of chronic infection with hepatitis B and C.