The clinical risk index for babies (CRIB) score is a risk-adjustment instrument widely used in neonatal intensive care. Its appropriateness with contemporary data has been questioned. We have examined these questions, developed a new five-item CRIB II score with data from a UK-wide sample of infants admitted to neonatal intensive care in 1998-99, and shown how mortality after neonatal intensive care has fallen in the past 12 years. CRIB II provides a recalibrated and simplified scoring system that avoids the potential problems of early treatment bias. A valid and simple method of risk-adjustment for neonatal intensive care is important to ensure accurate assessment of quality of care. Such assessments should be done in tandem with national audit systems for neonatal intensive care, incorporating measures of morbidity as well as mortality.