D-dimer and fibrin monomer both reflect a prothrombotic potential. There are limited data available comparing these two markers of activated coagulation in a prospective manner in an unselected patient population presenting to the emergency department with chest pain. In addition, their role in risk stratification in patients with acute coronary syndrome is still under evaluation. Therefore, we wanted to assess the prognostic value of these markers with respect to long-term all-cause mortality in 871 patients admitted to the emergency department. Blood samples were obtained immediately following admission. After a follow-up period of 24 months, 123 patients had died. In the univariate analysis, both D-dimer and fibrin monomer predicted all-cause mortality within 2 years with an odds ratio of 7.78 (95% confidence interval, 3.95-15.33) and 4.19 (95% confidence interval, 2.42-7.28), respectively, in the highest quartile (Q4) compared with the lowest quartile (Q1). However, in the multivariable logistic regression model for death within 2 years, the odds ratio of D-dimer and fibrin monomer was 1.80 (95% confidence interval, 0.81 to 3.97) and 1.04 (95% confidence interval, 0.53 to 2.04) in Q4 compared with Q1, respectively, and added no prognostic information above and beyond age, known coronary heart disease, B-type natriuretic peptide and the index diagnoses of ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction and unstable angina pectoris. In an unselected patient population hospitalized with chest pain and potential acute coronary syndrome, neither D-dimer nor fibrin monomer provided complementary prognostic information to established risk determinants during long-term follow-up.