ABSTRACT Objectives To assess the association between time spent in care, the childcare energy-balance environment, and preschool-aged children’s Body Mass Index z-score (z-BMI), waist-to-height ratio (WHR), and sum of skinfolds thickness (SST). Design Cross-sectional study. Setting and participants 3-to-4-year-old children were recruited from 30 childcare centres in Cambridgeshire (UK) in 2013. Main outcome measures Objectively measured height and weight was used to calculate BMI z-score; waist circumference and height were used to generate WHR; subscapular and tricep skinfolds were used to calculate SST. Associations between childcare attendance, the nutrition, physical activity, and overall childcare environment, and three anthropometric outcomes were explored using two-level hierarchical regression models, adjusting for demographic and family-based confounders. Results Valid data were available for 196 children (49% female). Time spent in care, the nutrition, physical activity, and overall childcare environment were not associated with children’s z-BMI score, WHR, and SST. Conclusions Childcare environment and level of attendance were not associated with UK preschool-aged children’s anthropometry. The childcare environment has been central to intervention efforts to prevent/ reduce early childhood obesity, yet other factors, including child-, family-, wider environmental, and policy-level factors warrant substantial attention when considering obesity prevention strategies for young children.