We report a case of intrauterine exposure to niflumic acid in a preterm neonate (35 weeks of gestation). The mother received niflumic acid (750 mg daily) during the last four days of gestation. Severe oligohydramnios was present. A transient neonatal renal failure, but also abdominal complications were observed for several days. Maternal and neonate niflumic acid levels were studied and showed an important placental transfer. Niflumic acid is a prostaglandin synthetase inhibitor. It is important that the nephrotoxicity of this vasoactive drug be known. Maternal administration of niflumic acid during the last days of gestation can induce fetal and neonatal adverse effects, especially renal failure. Prescription of all nonsteroidal anti-inflammatory drugs must be very cautious during pregnancy.