This article summarizes the principal characteristics of the drugs used to treat viral infections, with the exception of human immunodeficiency virus infection. It includes antiviral agents active against herpes virus, cytomegalovirus, hepatitis B and C virus, and respiratory viruses, such as influenza and respiratory syncytial virus. Dosage according to the indication, dose adjustment in the case of renal or hepatic insufficiency, significant pharmacokinetic characteristics, and the main adverse effects and interactions are described.