OBJECTIVE The relationship between lactate and mortality in patients without hypotension has not been appropriately explored. Our aim was to determine the usefulness of serum lactate as a prognostic factor of 28-day mortality in patients admitted to the Emergency Department with clinical diagnosis of sepsis without septic shock. METHODS We performed a secondary analysis of the study The epidemiology of sepsis in Colombia, a prospective cohort of patients from 10 general hospitals in 4 Colombian cities. We analyzed patients without hypotension with serum lactate available and admitted with community-acquired infections, which were confirmed according to the Centers for Disease Control and Prevention CDC criteria. A logistical regression was performed adjusting for age, sex, comorbidities and severity scores. RESULTS We included 961 patients aged 57.2 ± 21.0 years, 54.2% were females, mean SOFA score was 3.0 ± 2.3 and APACHE score was 11.1±6.4. We observed a linear relationship between serum lactate and the odds of death, and after adjustment there was a significant and independent association between lactate and mortality (odds ratio 1,16, 95% confidence interval 1.02-1.33). CONCLUSIONS Serum lactate is independently and significantly associated with 28-day mortality among patients with infection who present to the Emergency Department without hypotension. Besides, mortality increases in a linear way with serum lactate from any detectable value.