This study sought to examine the incidence of sudden death in a large, multiethnic cohort of young women. Approximately 852,300 women entered basic military training from 1977 to 2001. During this period, there were 15 sudden deaths in female recruits (median age 19 years, 73% African-American), occurring at a median of 25 days after arrival for training. Of the sudden deaths, 13 (81%) were due to reasons that may have been cardiac in origin. Presumed arrhythmic sudden death in the setting of a structurally normal heart was seen in 8 recruits (53%), and anomalous coronary origins were found in 2 recruits (13%). The mortality rate was 11.4 deaths per 100,000 recruit-years (95% confidence interval 6.9 to 18.9). The rate was significantly higher for African-American female recruits (risk ratio 10.2, p <0.001). Sudden death with a structurally normal heart was the leading cause of death in female recruits during military training.