On June 20, 2011, an emergency department (ED) physician reported five epidemiologically linked measles cases to the Indiana State Department of Health. The subsequent investigation identified a total of 14 confirmed cases in northeast Indiana. Of these, 10 were laboratory-confirmed, and four were among household contacts of persons with laboratory-confirmed measles. Of the 14 patients, 13 were unvaccinated persons in the same extended family. The nonfamily member was a child aged 23 months who had received 1 dose of measles, mumps, and rubella vaccine 4 months before illness onset. Four of the 14 patients were males; median age was 11.5 years (range: 15 months-27 years). One patient was a woman in week 32 of pregnancy who was hospitalized for acute pneumonitis.