Widespread use of antibiotics in hospitalized patients contributes to the development of multidrug resistant organisms that make many infections increasingly difficult to treat. Despite calls to prescribe antibiotics judiciously, many physicians continue to order antibiotics for inpatients who do not need them. This Issue Brief investigates antibiotic use in hospitalized adults with a confirmed viral infection, a group of patients that may not benefit from such therapy. Understanding the factors that lead to inappropriate antibiotic use may help change clinical practice and limit antibiotic resistance.