Objectives. To describe the adaptive behaviors in a large sample of homeless children and identify factors associated with developmental delay. Methods. Data were from a cross-sectional survey of 557 children younger than 6 years randomly sampled among homeless sheltered families in the Paris region, France (January\textendash May 2013). An interviewer and a psychologist conducted face-to-face interviews to collect information on sociodemographic and health characteristics. We assessed adaptive behaviors using the Vineland Adaptive Behavior Scales, second edition (VABS-II). Results. The mean VABS-II composite score (SD) was 75.4 (12.0), and most participating children (80.9%) were considered developmentally delayed. Characteristics negatively associated with children's developmental score were age, birth in a country other than France, low birth weight, and past-year hospitalization. Conclusions. There is a high prevalence of developmental delays among children growing up homeless. Public Health Implications. Long-term integrated programs improving parenting and children's opportunities for stimulation and socialization should be developed in daycare centers, schools, shelters, and medical practices to minimize negative effects of early living conditions on children's development.