A retrospective study of all premature neonates who received artificial surfactant (Curosurf) at the Rotunda Hospital was performed. The period from October 1990 to June 1992 (n = 48) was compared with the initial experience from June 1987 to January 1988 (n = 15). In the initial period mortality rate was 67% in surfactant treated infants, and use of surfactant was not associated with an improvement in outcome compared with the previous six years. In the more recent period overall mortality was 21%. Overall survival in normally formed very low birthweight infants improved from 59% in 1986 to 86% in 1991-1992. Improvement in survival rates was most noticeable in infants with birthweight 750-999 grams, with survival increasing from 44% (before introduction of surfactant treatment) to 91% (in 1991-1992). It is probable that a certain level of experience with use of surfactant is required before optimal effects can be obtained.