•CoC associated with higher teacher ratings of child self-control, initiative, and attachment while in infant-toddler rooms.•CoC associated with fewer teacher-rated behavioral concerns while children were enrolled in infant-toddler classrooms.•No consistent relation of CoC with preschool teachers’ ratings of self-control, initiative, attachment or language at age 3.•Findings do not provide clear support for CoC, but suggest a need for additional research.•Future research needed to fully examine associations with child outcomes and impacts on teachers, families, and peers. Ensuring that young children, especially infants and toddlers, experience consistency in child care providers over time is a practice endorsed by multiple professional organizations. This practice, commonly referred to as continuity of care (CoC), is recommended for center-based group settings to provide infants and toddlers with the sensitive, responsive care needed to promote early development. Despite widespread endorsement, there has been limited empirical examination of CoC. This study examines the extent to which CoC experienced in infant-toddler center-based care is associated with social-emotional and language development. Associations of CoC with children’s social-emotional development during the infant-toddler period and with later social-emotional and language outcomes at age 3 were investigated in a large sample of children attending high-quality early childhood programs designed for young children growing up in poverty. During the infant-toddler years, CoC was related to higher teacher ratings of self-control, initiative, and attachment, and lower ratings of behavior concerns. In addition, a classroom quality×CoC interaction indicated that CoC differences were larger in higher, than lower, quality infant-toddler classrooms. In contrast, CoC in infant-toddler classrooms was not related to rates of change in teacher ratings of social skills during the infant-toddler years nor to children’s vocabulary development or ratings of social skills after they transitioned to preschool. Neither were there quality×CoC interactions at preschool. These findings do not provide clear support for the current widespread recommendations for CoC, but suggest a need for additional research. The need for future research to more fully understand associations with child outcomes as well as to examine potential impacts of CoC on teachers, families, and peers is highlighted.