Acute renal failure (ARF) is a common problem in the neonatal intensive care unit (NICU). In most cases, ARF is associated with a primary condition such as sepsis, metabolic diseases, perinatal asphyxia and/or prematurity. This retrospective study investigated the course of illness, therapeutic interventions, early prognosis and risk factors associated with development of ARF in the neonatal period. A total of 1311 neonates were treated in our NICU during the 42‐month study period, and 45 of these babies had ARF. This condition was defined as serum creatinine level above 1.5 mg/dL despite normal maternal renal function. The data collected for each ARF case were contributing condition, cause and clinical course of ARF, gestational age and birth weight, age at the time of diagnosis, treatment, presence of perinatal risk factors and need for mechanical ventilation. The frequency of ARF in the NICU during the study period was 3.4%. Premature newborns constituted 31.1% of the cases. The mean birth weight in the group was 2863 ± 1082 g, and the mean age at diagnosis was 6.2 ± 7.4 days. The causes of ARF were categorized as prerenal in 29 patients (64.4%), renal in 14 patients (31.1%) and postrenal in 2 patients (4.4%). Forty‐seven percent of the cases were nonoliguric ARF. Asphyxia was the most common condition that contributed to ARF (40.0%), followed by sepsis/metabolic disease (22.2%) and feeding problems (17.8%). Therapeutic interventions were supportive in 77.8% of the cases, and dialysis was required in the other 22.2%. The mortality rate in the 45 ARF cases was 24.4%. Acute renal failure of renal origin, need for dialysis, and need for mechanical ventilation were associated with significantly increased mortality (p < 0.05). There were no statistical correlations between mortality rate and perinatal risk factors, oliguria, prematurity or blood urea nitrogen and creatinine levels. The study showed that, at our institution, ARF in the neonatal period is frequently associated with preventable conditions, specifically asphyxia, sepsis and feeding problems. Supportive therapy is effective in most cases of neonatal ARF. Acute renal failure of renal origin, need for dialysis, and need for mechanical ventilation were identified as indicators of poor prognosis in these infants. Early recognition of risk factors and rapid effective treatment of contributing conditions will reduce mortality in neonatal ARF.