This study examined relative hazards for mortality and functional limitations according to poor self-ratings of health using prospective data from the NHANES I Epidemiologic Follow-up Study, a representative sample of US adults aged 25-74 years that has been followed since the First National Health and Nutrition Examination Survey (NHANES I) was conducted in 1971-1975. Follow-up data were taken from death records and from the 1982 and 1992 reinterviews. Respondents (n = 6,913) provided extensive baseline data through physician examinations, laboratory testing, and self-reports of conditions, symptoms, and risk behaviors. Functional limitations were assessed among survivors in 1982 and 1992. Cox regression models accounting for sample design indicated that baseline self-rated health was associated with a significantly reduced hazard of mortality for males but not for females through 1992; adjusted hazards ratios for excellent health as compared with poor health were 0.52 for males (95% confidence interval: 0.36, 0.73) and 0.80 for females (95% confidence interval: 0.51, 1.23). Self-rated health also predicted 1982 and 1992 functional limitation for both men and women and 1992 function net of 1982 function for men only. Self-rated health contributes unique information to epidemiologic studies that is not captured by standard clinical assessments or self-reported histories, but evidence suggests that the effect may be stronger for men than for women.