To assess the relationship between specific neonatal variables and subsequent mental development, a longitudinal study of 41 children from a high-risk neonatal nursery was conducted. For each child, 58 measures of neonatal condition (e.g., head size, various laboratory values, delivery mode) were available, as were developmental assessments up to 6 years of age. Mental status instruments used included the Stanford Binet, the Peabody Picture Vocabulary Test, the Beery Developmental Test of Visual Motor Integration, the Wechsler Preschool and Primary Scale of Intelligence, and the Vineland Social Maturity Scale. Each variable relating to neonatal condition was correlated with performance at 6 years for each test. Multiple stepwise regression analyses were computed for all neonatal condition variables; each individual test constituted the criterion variable. Results suggested that at 6 years of age specific neonatal conditions may affect specific aspects of mental function more than they affect global aspects of mental status. (Extensive tables of data and Pearson correlation coefficients are provided.) (RH)