Background Outdoor free play is important for healthy growth and development in early childhood. Recent studies suggest that the majority of time spent in daycare is sedentary. The objective of this study was to determine whether there was an association between daycare attendance and parent-reported outdoor free play. Methods Healthy children aged 1-5 years recruited to The Applied Research Group for Kids! (TARGet Kids!), a primary care research network, were included. Parents reported daycare use, outdoor free play and potential confounding variables. Multivariable linear regression was used to determine the association between daycare attendance and outdoor free play, adjusted for age, sex, maternal ethnicity, maternal education, neighborhood income and season. Results There were 2810 children included in this study. Children aged 1 to 3 years (n = 1388) and [greater than or equal to] 3 to 5 years (n = 1284) who attended daycare had 14.70 min less (95% CI -20.52, -8.87; P 0.01) and 9.44 min less (95% CI -13.67, -5.20; P 0.01) per day of outdoor free play compared with children who did not attend daycare, respectively. Conclusions Children who spend more time in daycare have less parent-reported outdoor free play. Parents may be relying on daycare to provide opportunity for outdoor free play and interventions to promote increased active play opportunities outside of daycare are needed. (author abstract)