The time children spend in child care overlaps with daily meals and opportunities to be active. Thus these environments have the opportunity to promote-or hinder-healthy weight gain among children who attend them. The purpose of this narrative review was to compile findings from studies examining child-care type and weight outcomes among preschool-age children. A literature search was conducted using PubMed, PsychInfo, and ERIC. Inclusion criteria were infant-to-5-year-old children exposed to any type of child-care with a cross-sectional or longitudinal weight outcome. Among 385 studies screened, 18 were included. For comparison across studies, type of child-care was categorized as: child-care center, Head Start, nanny/babysitter, non-relative care/family child-care home, and relative care. Four studies found no association with child-care type and obesity, and 10 studies reported mixed results by type of care or subpopulation analyses. Two studies found an overall positive association, and two reported an inverse association. There were differences in direction of associations and findings by type of care arrangement. For Head Start, three of eight studies demonstrated a negative relationship with obesity; none demonstrated a positive association. No other child-care type demonstrated this inverse association. Informal types of care (relative and non-relative care in a home) were positively associated with child obesity in 3 of 10 studies. This association was less commonly reported among formal child-care centers (2 of 15 studies). The majority of studies, however, reported mixed findings or no association by child-care type. Results suggested no consistent evidence for a relationship between child-care and obesity risk, except Head Start. This review exposed the need for a consistent definition of child-care type and the exploration of unmeasured confounders, such as the nutrition and physical activity environment of child-care settings, to understand how they contribute to or protect against the development of overweight/obesity among children.International Journal of Obesity accepted article preview online, 04 November 2016. doi:10.1038/ijo.2016.198.