Background This two-wave prospective study aims to apply self-determination theory (SDT) to understand how parents are motivated to protect their young children from COVID-19. We hypothesised that psychological need support from society and autonomous motivation from parents were predictive of parent's future engagement in preventive behaviours against COVID-19 for their children.

Methods Participants were 689 US parents or legal caregivers of 3- to 8-year-old children. They completed an online survey comprising previously validated measures of psychological need support, autonomous motivation from SDT and behavioural adherence to COVID-19 prevention at baseline and a 1-month follow-up. Confirmatory factor analysis and structural equation modelling were employed to test the hypothesised relationships.

Results Structural equation modelling revealed that psychological need support and autonomous motivation at baseline were positively related to parents’ adherence to COVID-19 preventive behaviours at follow-up.

Conclusion The findings suggest that the provision of autonomy-supportive and need-satisfying social environments may promote greater COVID-19 preventive behaviours in parents for their children and provide formative evidence to inform future interventions.