The atypical measles syndrome is a relatively new disease that was first recognized 15 years ago. Initially, it occurred in children who were exposed to wild measles virus several years after they were immunized with killed measles vaccine. It was characterized by a two- to three-day prodrome of high fever, cough, headache, and myalgia followed by a rash that resembled Rocky Mountain spotted fever, scarlet fever, or varicella and associated with roentgenographic evidence of pneumonia with or without pleural effusion. This report highlights three unusual manifestations of this syndrome: 1) transient hepatitis, 2) persistence of pulmonary lesions for several years, and 3) occurrence of excessively high measles hemagglutination-inhibition antibody titers. Today, this syndrome occurs predominantly in adolescents and young adults.