Acute renal failure (ARF) occurs in wide range of conditions, making the evaluation of its prognosis a difficult task. Data regarding prognostic factors in ARF in a general population in developing countries are scarce. The objective of the study was to describe predictors of mortality in ARF that are relevant in the developing world. This prospective study was carried out over a one-year period; all hospitalized adults with ARF were included in the study. Predictors of mortality studied included causes of ARF, pre-existing diseases, and severity as well as complications of ARF. Of 33,301 patients admitted during the study period, 294 (0.88%) were either admitted with or developed ARF after hospitalization. Mean age was 43.9 +/- 16.9 (18-86 yrs). Sepsis was the most common cause (63.26%). Pre-existing diseases like cardiovascular disease (CVSD), respiratory system disease (RSD), central nervous system disease (CNSD), hypertension, diabetes mellitus (DM), and malignancy were significantly higher in elderly as compared to younger patients. On univariate analysis sepsis, hypoperfusion as a cause of ARF and hospital-acquired ARF were associated with higher mortality. Pre-existing diseases viz. RSD, CVSD, CNSD, and DM had higher mortality. Among the severity and complications of ARF, oliguria, bleeding and infection during the course of ARF and critical illness were predictors of poor outcome. Age > 60 yrs was associated with significantly higher mortality. However, on multivariate analysis, only critical illness (odds ratio 37.3), age > 60 years (odds ratio of 5.6), and sepsis as cause of ARF (odds ratio of 2.6) were found to be independent predictors of mortality.