The relation between plasma fibrinogen and total and cause-specific mortality was investigated in a cohort of 3571 Japanese-American men aged 71 to 93 years during a median follow-up of 4.4 years. There were a total of 728 deaths, of which 37% were accounted for by cardiovascular disease and 27% by cancer. The age-adjusted relative risk (RR) for total mortality in the top quintile of fibrinogen (>3.51 g/L) compared with the bottom quintile (<2.57 g/L) was 4.3 (P<0.0001) in the first year of follow-up. RR was reduced to 1.7 in the second year but remained significantly and slightly increased in subsequent years. After adjustment for age and confounding risk factors, the RRs (and 95% confidence intervals) associated with a 1-SD increment of fibrinogen (0.64 g/L) for all-cause, cardiovascular disease, cancer, and other-cause mortality were 1.3 (1.2 to 1.4), 1.2 (1.1 to 1.4), 1.3 (1.2 to 1.5), and 1.3 (1.2 to 1.5), respectively. Preexisting diseases did not influence the significant association of fibrinogen with mortality. There was a significant interaction of fibrinogen with white blood cell count but not with cigarette smoking. We conclude that plasma fibrinogen is an independent risk factor for mortality from a broad spectrum of diseases in elderly men and that this universal effect of fibrinogen on mortality may be mediated partly through inflammation.