Hepatitis is an inflammation of the liver with hepatocellular damage ranging from mild to severe to potentially fatal. Viral hepatitis is caused by six hepatotropic viruses: hepatitis A (HAV), B ( HBV), C (HCV), D (HDV), E ( HEV), and G ( HGV). Autoimmune hepatitis (AIH) is a generally unresolving inflammation of the liver of unknown cause. Patients with acute hepatitis should be monitored until liver function tests become normal. This chapter reviews the hepatotropic viruses. Although HAV, HBV, and HCV are the viruses most commonly encountered in the United States, It considers HDV, HEV, and HGV as well. Other viral causes of inflammation of the liver include adenovirus, Epstein-Barr virus, cytomegalovirus, rubella, herpes simplex, varicella, and parvovirus. Primary care providers must identify the virus causing liver damage, care for patients with these viral infections, and protect the community as well as themselves from exposure to these viruses.