This three-part study of early identification of developmental deficiencies in high risk infants was undertaken to determine whether infant performance can be predicted from neonatal and developmental criteria. Part I of the study began in 1977 and used 284 high risk infants as subjects. Part II was initiated in 1978. Subjects were 14 full-term, and 10 premature infants. Part III, initiated in 1979-80, evaluated 119 hospitalized high risk infants. In general, the "Neonatal Behavioral Assessment Scale" (NBAS), in combination with medical histories and developmental assessments, was found to predict mental and motor performance at 9 months on the "Bayley Scales of Infant Development" (BSID). NBAS assessments at as early as 30 weeks gestational age were found related to BSID assessments at 2, 3, and 4 months of age. Patterns of pre-term infant performance on the NBAS emerged at 35 weeks gestational age. Discriminate analysis yielded one hundred percent prediction of 9-month performance on the BSID and pre-term or full-term group membership. NBAS subscales and medical histories provided 3 of 4 predictors of normal function and 11 of 11 predictors of abnormal function. The study concludes that a neonatal interdisciplinary involvement with "at risk" or pre-term infants and earlier intervention for those infants with special needs. (Author/CM)