The role of childcare educators is important given that 81% of preschoolers living in developed countries receive childcare outside their home. Since children learn by observing and imitating others, childcare educators may play a role in promoting healthy eating behaviours and physical activity in young children. Six databases were searched for quantitative peer-reviewed, English or French primary studies reporting the correlates, predictors or effectiveness of childcare educators' practices on preschoolers' healthy eating and physical activity behaviours. Risk of bias was assessed using the Quality Assessment Tool for Quantitative Studies. Fifteen articles were included in this review: 10 measured physical activity levels and five assessed eating behaviours. The quality score was rated as low for eight of these articles, and as moderate for the remaining seven. Two of four cross-sectional studies reported a positive relationship between educators and children's behaviours. Eleven intervention studies reported significant favourable effects of interventions. Educators may play a positive role in promoting healthy behaviours in children, but this is mainly based on a small number of intervention type studies of low or moderate quality. The influence of specific components of educators' practices on children's healthy eating and physical activity behaviours remains inconclusive. (author abstract)