Urine output following administration of a low‐dose dopamine infusion was assessed in 20 very immature infants (median gestational age 27 weeks). Prior to the infusion, all infants had had a period of anuria. Urine output improved significantly during the second 24 h after commencing the infusion but, at that time period, urine output was greater than 2 ml/kg/h (designated a good response) in only 13 infants. There was no significant difference in gestational age, birth weight, period of anuria or fluid input of infants who had a good or a poor response to dopamine. Although the baseline blood pressure did not differ significantly between these two groups, the increase in blood pressure resulting from dopamine administration was significantly greater in those infants with a good response in urine output (p<0.02). We conclude that low‐dose dopamine infusion can improve urine output in very immature infants. Our results suggest that there may be inter‐individual variation in the sensitivity to dop