A 38-year-old female with a two-week history of amoxicillin use for fever, cough, and coryza presented with two days of erythematous chest macules. Despite discontinuation of the antibiotic, her rash continued; measles was diagnosed with IgM titers. Three weeks previously she had returned from China. She had received only one vaccination despite travel to this measles-endemic area. Vaccination and herd immunity have reduced the measles prevalence in America by more than 99%; travel, foreign adoption, and refusal of vaccination have, however, increased the risk.