During the 12-year follow-up, there were 710 deaths. Women with a low BMI at age 18 years had no extra risk for death when compared with those who were of normal weight, but a higher-than-normal BMI at age 18 years was associated with a higher risk for death. Although smokers in all BMI categories were at greater risk for death than nonsmokers, adjusting for smoking status did not eliminate the risk for death associated with obesity at age 18 years. Causes of death during follow-up in those with elevated BMI at age 18 years included cancer, cardiovascular disease, and suicide.