Objective: Despite public health efforts, most children in the USA do not meet nutrition and physical activity guidelines. Moreover, there are nutrition-related health disparities between non-Hispanic and Hispanic communities. Caregivers are critical role models that shape health behaviours in children. To promote healthy behaviours, health promotion interventions must consider the entire family unit. This study aimed to assess the impact of parent's health behaviours on children's health behaviours in a sample of non-Hispanic and Hispanic low-income parents. Design: A mixed-methods design was used to identify how parent health behaviours including fruit and vegetable intake, beverage intake, physical activity, and screen time influence corresponding child health behaviours. In addition, the study aimed to investigate whether the strength of association between parent and child health behaviours varied as a function of ethnicity. Survey data and semi-structured qualitative interviews were utilised for the analyses. Setting: The study was a part of the Culture of Wellness in Preschools Programme, a multi-level obesity prevention programme. The data were obtained from the parent wellness workshops, a direct education intervention aimed at increasing fruit and vegetable consumption and physical activity among parents and their children. Data Analysis: The quantitative analyses utilised survey data from the Family Wellness pre-survey. Hierarchical linear regression models assessed the relationship between parent-child-health behaviours. Interaction terms were created to understand if this relationship varied as a function of ethnicity. Data from qualitative interviews were analysed using thematic analysis to gain an in-depth understanding of the relationship between parent and child health behaviours. Results: Parent health behaviours significantly predicted child health behaviours across all models, and these relationships did not vary as a function of ethnicity. The quantitative data were supported by the qualitative analysis: parents modelled health behaviours and thus influenced their child's health behaviour through a variety of mechanisms. Conclusion: Future efforts to promote a healthy lifestyle in children should engage with both family practices and the wider social context.