On August 26, 1992, a 31-year-old male resident of Tucson, Arizona, died of an illness subsequently diagnosed as primary pneumonic plague. This is the 10th case of plague reported in the United States in 1992, the first pneumonic plague case this year, and the first plague fatality reported since 1987 (CDC, unpublished data). This report summarizes the investigation of this case by county, state, and federal public health officials in Arizona and Colorado.