Measles virus is an epidemic disease with a worldwide distribution. Since the development of the live attenuated vaccine, the incidence of reported measles cases has declined by greater than 99% in the United States. Measles causes a systemic illness manifested by a characteristic prodrome and pathognomonic rash. Although usually a self-limited disease, measles can cause severe complications, especially in adults and the immunocompromised. We discuss a vaccination schedule for preschool and school-aged children. Recent research has demonstrated clinical benefit in patients with severe measles virus infections that are treated with ribavirin and vitamin A supplementation.