Febrile illnesses are a major cause of mortality in sub-Saharan Africa. Early identification of patients at increased risk of death may avert adverse outcomes. We aimed to independently evaluate the performance of the Modified Early Warning Score, quick Sequential Organ Failure Assessment (qSOFA) score, and Integrated Management of Adolescent and Adult Illness (IMAI) emergency signs and severity criteria to predict in-hospital mortality among a prospective cohort of febrile patients in Tanzania. We evaluated 419 patients aged ≥ 10 years in the period 2007-2008. Of the 44 patients who died, 31 (70.5%) were human immunodeficiency virus (HIV) infected. On univariate analysis, in-hospital mortality was associated with HIV infection, oxygen saturation