Acute renal failure (ARF) is an important cause of morbidity and mortality in children. Here, we investigate etiology, comorbidities, outcome and risk factors associated with mortality in these children with ARF. We retrospectively reviewed the characteristics of 58 children with ARF diagnosed between January 1997 and December 2006 at a single institute. Factors including age, sex, clinical features and laboratory parameters were compared between survivors and non-survivors. ARF was secondary to extrarenal causes in 79.3% of cases. Sepsis (18.9%), hematooncologic disease (18.9%) and cardiovascular disease (18.9%), were the main causes of ARF. Primary renal disease due to acute glomerulonephritis, nephrotic syndrome, hemolytic uremic syndrome and obstructive uropathy accounted for 20.7% of the cases. The overall mortality rate was 51.7%. There were no significant differences between survivors and non-survivors in gender and changes in the peak levels of calcium, phosphorous and uric acid levels. The mortality rate was significantly higher when ARF occurred in younger children (p = 0.019), secondary to systemic disease (p = 0.038, odds ratio 4.3; 95% confidence interval (CI) 1.0, 17.9), sepsis (p < 0.001, odds ratio 19.7; 95% CI 5.1, 76.4), use of ventilator (p < 0.001, odds ratio 35; 95% CI 6.7, 182.7), multiple organ failure (p < 0.001) and non-use of renal replacement therapy (p = 0.018, odds ratio, 3.6; 95% CI interval 1.2, 10.6) on univariate analysis. Multiple logistic regression analysis revealed that sepsis (p = 0.011, odds ratio, 11.3; 95% CI 1.7, 73.0) and numbers of organ failures (p = 0.001, odds ratio 8.14; 95% CI 2.5, 26.7) were independently associated with mortality. This study found that sepsis and number of organ failures were independent predictors of mortality in children with ARF.