The medical care of children with acute renal failure and the necessity of the substituting the renal functions has dramatically modified over the past 15 years. The study has been conducted retrospectively on 35 children diagnosed with acute renal failure (ARF), for analyzing the etiological spectrum, the evolutionary patterns and the influence factors of the ARF evolution. The following parameters have been taken into consideration: ARF etiology, hTA/HTA, oliguria, level of serum creatinine, the type of treatment (renal substitution by hemodialysis, peritoneal dialysis, or conservative treatment). The ARF etiology is dominated by the sepsis (31.4%) and by the hemolytic and uremic syndrome (17.1%). The treatment applied was conservative in 48.5% of the cases; 51.50% of the patients were in critical state and required extrarenal substitution by hemodialysis--42.8%--and peritoneal dialysis--8.5%. Global mortality is reduced (22.8%), but in the dialysed patients it is of 44.44%. The main death causes were: severe hepatic failure, oncological diseases, severe neurological damage and hemodynamic damages. In conclusion, the ARF prognosis in children is influenced by the comorbidity states. Dialysis has improved the therapeutic results in the currently presented lot, the death causes being extrarenal.