We evaluated the economic aspects of neonatal intensive care of very-low-birth-weight infants, using outcomes and costs of care before and after the introduction of a regional neonatal-intensive-care program. Neonatal intensive care increased both survival rates and costs. For newborns weighing 1000 to 1499 g, the cost (in 1978 Canadian dollars) was $59,500 per additional survivor, $2,900 per life-year gained, and $3,200 per quality-adjusted life-year gained; intensive care resulted in a net economic gain when figures were undiscounted but a net economic loss when future costs, effects, and earnings were discounted at 5 per cent per annum. For infants weighing 500 to 999 g, the corresponding costs were $102,500 per additional survivor, $9,300 per life-year gained, and $22,400 per quality-adjusted life-year gained; intensive care resulted in a net economic loss. By every measure of economic evaluation, the impact of neonatal intensive care was more favorable among infants weighing 1000 to 1499 g than among those weighing 500 to 999 g. A judgment concerning the relative economic value of neonatal intensive care of very-low-birth-weight infants requires a comparison with other health programs.