The development and dissemination of neonatal intensive care technology has been associated with improved survival for critically ill newborn infants, particularly those with birth weights of less than 1,500 grams (3 pounds, 5 ounces). Despite these advances, there are concerns about the long-term health status of surviving infants and the costs of their initial and subsequent care. In this article, the authors review current evidence for the effectiveness of neonatal intensive care and discuss several approaches to evaluating neonatal intensive care technology. They discuss a four-step process originally proposed by Roper for assessing and improving neonatal intensive care practices which includes (1) monitoring of practices, outcomes, and costs; (2) analysis of variation in practices, outcomes, and costs; (3) assessment of the efficacy of individual interventions, and (4) feedback and education to alter clinical behavior. The authors conclude that organized networks of neonatal intensive care units can play a crucial role in this process.