To achieve adequate arterial BP, adequate capillary filling time, and adequate peripheral pulses, hypotensive newborn infants often require higher doses of dopamine that reportedly reduce urine output in adults. Whether these larger doses of dopamine also reduce urine output in newborns is not known. Therefore, we determined the effects of administering high-dose dopamine (more than 20 micrograms/kg X min) on the urine output of 15 newborn infants. Five infants were studied prospectively and ten retrospectively. In the prospective study, urine output was determined as the dose of dopamine was increased; in the retrospective study, urine output was determined as the infants were being weaned from high doses of dopamine. Both data sets demonstrate that administering high-dosage dopamine does not reduce the urine output of sick newborn infants. Therefore, we conclude that doses of dopamine previously reported to decrease urine output in adults do not do so in sick newborn infants. Consequently, when necessary, high doses of dopamine may be used in sick newborn infants to achieve cardiovascular stability without reducing urine output.