To measure the psychological and emotional effects of the September 11, 2001, terrorist attacks on the World Trade Center (WTC), Connecticut, New Jersey, and New York added a terrorism module to their ongoing Behavioral Risk Factor Surveillance System (BRFSS). This report summarizes the results of the survey, which suggest widespread psychological and emotional effects in all segments of the three states' populations. The findings underscore the importance of collaboration among public health professionals to address the physical and emotional needs of persons affected by the September 11 attacks.