Several studies have suggested that a young age at menopause may be associated with increased risk of all-cause mortality. Few studies have examined the influence of age at menopause on specific causes of death other than coronary heart disease. Data from a prospective cohort study of US adults were used to examine the relation between age at natural menopause and all-cause and cause-specific mortality among women who never used hormone replacement therapy, who never smoked, and who experienced natural menopause between the ages of 40 and 54 years. After 20 years of follow-up between 1982 and 2002, 23,067 deaths had occurred among 68,154 women. Results from Cox proportional hazards models showed that all-cause mortality rates were higher among women who reported that menopause occurred at age 40-44 years compared with women who reported that menopause occurred at age 50-54 years (rate ratio (RR) = 1.04, 95% confidence interval (CI): 1.00, 1.08). This increased risk was largely due to higher mortality rates from coronary heart disease (RR = 1.09, 95% CI: 1.00, 1.18), respiratory disease (RR = 1.19, 95% CI: 1.02, 1.39), genitourinary disease (RR = 1.39, 95% CI: 1.07, 1.82), and external causes (RR = 1.56, 95% CI: 1.21, 2.02). These findings suggest that mortality from other diseases, as well as coronary heart disease, may contribute to the increased mortality associated with a younger age at menopause.