Children with developmental disabilities often report having few friends. Researchers have tended to focus on social skill deficits, neglecting other potent predictors of children's feelings of loneliness. In a sample of 82 children with developmental disabilities, we examined characteristics of the child at age 3 (i.e., the conclusion of early intervention services) as well as family income and emotional climate as predictors of children's reported feelings of loneliness at school during middle childhood (age 10). Children with lower levels of externalizing behavior problems at age 3 and from families with a more positive family climate, as indicated by the Family Environment Scale, reported less loneliness at age 10. Implications for children, families, and early intervention services are discussed.