While many chronic illnesses are diagnosed in infancy, there is little systematic study of the impact of chronic illness on early social development and how parental adjustment to a chronically ill infant contributes to subsequent outcomes. This paper outlines some of the factors which affect parents' ability to care for chronically ill infants and preschoolers. It draws upon studies of infants with other medical problems, ongoing longitudinal study of infants with cystic fibrosis and congenital heart disease by the authors; and the authors' clinical experience.