Health planners and policy makers are increasingly asking for a feasible method to identify vulnerable persons with the greatest health needs. We conducted a systematic review of the association between a single item assessing general self-rated health (GSRH) and mortality. Systematic MEDLINE and EMBASE database searches for studies published from January 1966 to September 2003. Two investigators independently searched English language prospective, community-based cohort studies that reported (1) all-cause mortality, (2) a question assessing GSRH; and (3) an adjusted relative risk or equivalent. The investigators searched the citations to determine inclusion eligibility and abstracted data by following a standardized protocol. Of the 163 relevant studies identified, 22 cohorts met the inclusion criteria. Using a random effects model, compared with persons reporting "excellent" health status, the relative risk (95% confidence interval) for all-cause mortality was 1.23 [1.09, 1.39], 1.44 [1.21, 1.71], and 1.92 [1.64, 2.25] for those reporting "good,"fair," and "poor" health status, respectively. This relationship was robust in sensitivity analyses, limited to studies that adjusted for co-morbid illness, functional status, cognitive status, and depression, and across subgroups defined by gender and country of origin. Persons with "poor" self-rated health had a 2-fold higher mortality risk compared with persons with "excellent" self-rated health. Subjects' responses to a simple, single-item GSRH question maintained a strong association with mortality even after adjustment for key covariates such as functional status, depression, and co-morbidity.