The Child Development Inventory (CDI), completed by parents at home, assesses the development of social, self-help, motor, language, letter and number skills, and presence of symptoms and behavior problems of children between the ages of 15 months and 5 years. The results provide the pediatrician with a profile of the child's development, problems, and strengths, and are an aid to comprehensive assessment. CDI norms and validity were determined for a community sample of 568 children. The CDI developmental scales correlate closely with age (r = 0.84). CDI results identified all the normative group children who were enrolled in early childhood/special education (N = 26) and correlated with academic achievement for children in kindergarten (N = 132). CDI scales correlated with reading achievement in kindergarten as follows: general development 0.69, letters 0.56, language comprehensive 0.42, expressive language 0.36, and self-help 0.35. Thus, the CDI provides a useful measure of children's development and, because of its reliance on parental reports, offers an effective approach to developmental assessment in the busy pediatric practice.