A study was made to determine whether the high transepidermal water loss in preterm newborn infants is affected by infusion of human albumin. In 7 preterm infants, born after 25–30 weeks of gestation, 0.5 g of human albumin per kilogram body weight (b.w.) was infused through an umbilical artery catheter in 6 h on the 1st day after birth. In 2 other infants, born after 28 completed weeks of gestation, human albumin in an amount of 1.0 g/kg body weight was infused. The plasma albumin concentration increased significantly from a pre-infusion value of 27.1 to 29.5 g/l after 4 h of infusion. Simultaneously the transepidermal water loss decreased from 26.6 to 23.5 g/(m2·h); this difference was also significant. Within 2 h after the end of the albumin infusion, both the plasma albumin concentration and the transepidermal water loss had returned to levels that were not significantly different from the pre-infusion values. Plasma osmolality and sodium concentration did not alter during the infusion, nor did arterial blood pressure.