Recent meta-analyses of prospective studies have shown that plasma levels of both fibrinogen and fibrin D-dimer are independent predictors of ischemic heart disease. Although at present reported studies using different assays do not show heterogeneity, there is a need for prospective comparison of different assays, as well as for development of standards. Collaborative development of the clinical use of these risk predictors is also required. Finally, the causal significance of the associations of fibrinogen and D-dimer with thrombotic events remains to be established by randomized controlled trials of reduction in their plasma levels.