Gadopentetate dimeglumine (gadolinium diethylenetriaminepentaacetic acid [DTPA]) was prospectively administered to 15 consecutive neonates and young infants (less than 6 weeks old) referred for routine cranial magnetic resonance (MR) imaging. The goals of the study were (a) to provide preliminary safety and efficacy data concerning the use of this drug in neonates and (b) to determine whether the patterns and time course of normal contrast material enhancement were similar to those seen in older children and adults. Gd-DTPA-enhanced MR images revealed significant abnormalities not seen on the MR images obtained before administration of contrast material in four (27%) of 15 patients. The adult dose (0.1 mmol/kg) provided bright enhancement of normal intracranial structures. Because of significantly reduced glomerular filtration and renal clearance rates in newborns, vivid contrast enhancement of normal structures was seen to persist for several hours after injection. A prolonged window of time for imaging may therefore exist for neonates and young infants.