Objective: To identify independent factors associated with caregiver supervision levels at beaches. Methods: Children (aged 1-14 years) engaged in beach play and their caregivers were observed at Australian beaches during September-April, 2008/09. Caregiver, child, and environmental factor data were collected and recorded on a validated observation instrument. The main outcome of interest was a continuous measure of supervision. After adjusting for potential clustering by beach/state, multivariable linear regression was used to identify independent factors associated with caregiver supervision. Results: Four independent predictors of supervision and one interaction effect (child age by the caregiver and child position on beach) were identified. Caregivers who were supervising from a different position to where the child was playing were less likely to provide high supervision, as were older caregivers (>35 years) compared to younger caregivers (≤34 years). Compared to children playing alone, children playing with one, or two or more others were less likely to receive high supervision, and children aged 1-4 years were likely to receive higher supervision than older children. Conclusion: This study provides new knowledge about underlying factors associated with the level of caregiver supervision in beach settings. Future studies should continue to explore independent predictors of supervision so that effective programmes, which focus on caregiver supervision, can be targeted to address poor supervision practices.