This study presents research findings of a four year study intended to identify infant and family characteristics which, singly or in combination, predict developmental problems during preschool and school years. Predictors included a variety of measures of parental and neonatal biological conditions as well as measures of the quality of the social environment. These included tests of development and cognitive functioning (such as the Bayley Scales of Infant Development and the Stanford Binet Intelligence Scale), and assessments of social functioning based on parental reports. The initial sample consisted of 193 first-born infant/mother dyads who were enrolled in a pre-paid health insurance cooperative in Seattle, Washington. In general, correlations of weighted minor congenital anomalies scores with neonatal variables (birthweight, gestational age, and medical risk), behavior and cognitive measures, and level of home stimulation were all low. It was concluded that minor congenital anomalies are not important predictors of development during the course of childhood, given the important mediating effects of the psychosocial environment.