['The aim of the study was to determine whether C-reactive protein (CRP), procalcitonin (PCT), and d-dimer (DD) are markers of mortality in patients admitted to the emergency department (ED) with suspected infection and sepsis.', 'We conducted a prospective cohort in a university hospital in Medellín, Colombia. Patients were admitted between August 1, 2007, and January 30, 2009. Clinical and demographic data and Acute Physiology and Chronic Health Evaluation II and Sepsis Organ Failure Assessment scores as well as blood samples for CRP, PCT, and DD were collected within the first 24 hours of admission. Survival was determined on day 28 to establish its association with the proposed biomarkers using logistic regression and receiver operating characteristic curves.', 'We analyzed 684 patients. The median Acute Physiology and Chronic Health Evaluation II and Sepsis Organ Failure Assessment scores were 10 (interquartile range [IQR], 6-15) and 2 (IQR, 1-4), respectively. The median CRP was 9.6 mg/dL (IQR, 3.5-20.4 mg/dL); PCT, 0.36 ng/mL (IQR, 0.1-3.7 ng/mL); and DD, 1612 ng/mL (IQR, 986-2801 ng/mL). The median DD in survivors was 1475 ng/mL (IQR, 955-2627 ng/mL) vs 2489 ng/mL (IQR, 1698-4573 ng/mL) in nonsurvivors (P=.0001). The discriminatory ability showed area under the curve-receiver operating characteristic for DD, 0.68; CRP, 0.55; and PCT, 0.59. After multivariate analysis, the only biomarker with a linear relation with mortality was DD, with an odds ratio of 2.07 (95% confidence interval, 0.93-4.62) for values more than 1180 and less than 2409 ng/mL and an odds ratio of 3.03 (95% confidence interval, 1.38-6.62) for values more than 2409 ng/mL.'] Is d-dimer a significant prognostic factor in patients with suspected infection and sepsis?