To study the effects of infusion of low doses of dopamine hydrochloride on cardiopulmonary and renal status in premature newborns with respiratory distress syndrome, 49 newborns were randomly assigned to three groups: group 1 (18 patients) received no dopamine and was the control group; group 2 (16 patients) was infused with a dose of dopamine measuring 1.0 μg/kg of body weight per minute for 72 hours; and group 3 (15 patients) was infused with a dose of dopamine measuring 2.5 μg/kg of body weight per minute for 72 hours. Birth weights, gestational ages, postnatal ages, and cardiopulmonary status of all groups at the start of the study were comparable. Continuous infusion of these low doses of dopamine for 3 days after birth did not significantly improve levels of blood gases, acid-base balance, or clinical outcome. In newborns with systemic hypotension, dopamine improved cardiovascular status and caused early return of blood pressure to the normal range. Infusion of low doses of dopamine produced mild to moderate natriuresis and insignificant increases in glomerular filtration rate and urine volume.