Summary Objectives The aims of this study were to determine the mechanism of an outbreak of measles in adults and to provide scientific measures for putting forward a measles elimination program. Methods We performed a cross-sectional investigation during the measles outbreak to identify a possible communication link. Results From November 1, 2011 to January 26, 2012, the town reported 11 cases of measles in total. The case study identified an obvious propagation chain, which showed ordered and intimate exposure between cases. Conclusions Hospital exposure 1–2 weeks before infection with measles was the main cause of the measles outbreak. We must be fully aware of the possibility of nosocomial infection in an outbreak of measles; controlling nosocomial infections is a vital step in the prevention and control of the propagation of measles.