© 2021 BMJ Publishing Group. All rights reserved.Objectives Childhood obesity is increasingly prevalent in the developing world including Turkey. This study examined constructs of the integrated behavioural model associated with physical activity in a sample of schoolchildren in Ankara, Turkey using structural equation modelling. Design Cross-sectional survey by probability sampling. Setting Fifteen schools of different socioeconomic strata in Ankara, Turkey with grade 4 students. Participants 2066 (969 girls and 1097 boys) grade 4 schoolchildren and their parents selected using a probability-based sampling frame. Primary outcome measures Three primary outcomes were used: moderate-To-vigorous physical activity, team sport participation, sedentary behaviour. Results Data were collected from 2066 fourth-grade children from schools of three socioeconomic strata. Missing data were imputed using multiple imputation. To examine the integrated behavioural model, a structural equation model containing latent constructs for physical activity outcome expectancies, self-efficacy, home environment and social norms were fitted with the three outcomes above. Adequate model fit was achieved in the structural equation model (χ 2 =1821.97, df=872, p<0.001, Comparative Fit Index=0.91, Tucker Lewis Index=0.91, root mean square error of approximation=0.02, standardised root mean square residual=0.04). All scale items were significantly associated with their respective latent constructs (all p<0.001). Several significant pathways between latent constructs and outcomes of interest were observed (p<0.05). Self-efficacy was positively associated with moderate-To-vigorous physical activity (p<0.001) and team sport participation (p<0.001) and negatively associated with sedentary behaviour (p<0.001). Negative outcome expectancies were negatively associated with moderate-To-vigorous physical activity (p<0.01) and sedentary behaviour (p<0.01) while positive outcome expectancies were positively associated with team sport behaviour (p<0.001) and negatively associated with sedentary behaviour (p<0.05). Home support was positively associated with moderate-To-vigorous physical activity (p<0.01) and team sport participation (p<0.05). Finally, physical activity social norms were negatively associated with sedentary behaviour only (p<0.05). Conclusions This study supported the extension to Turkish children of the integrated behavioural model in relation to physical activity behaviours. Results illustrate multiple targets for interventions to increase physical activity.