Aims: To assess the acceptability and potential efficacy of an online healthy lifestyles program for parents of overweight, or at risk of overweight, preschool-aged children. Methods: A pilot trial was conducted within a regional area of New South Wales, Australia. Two cohorts totalling 47 dyads were recruited. Primary outcomes were parental self-reported perceived knowledge and parental proxy-reported behaviour of their child. Data analysis was completed using the Statistical Package for Social Sciences (v 16). Results: At follow up (10weeks) parents reported high acceptability of the program. Changes in the hypothesised direction were reported for all parental perceived knowledge and parental and child behavioural outcomes. Conclusion: This is the first study to describe the acceptability and potential efficacy of an online healthy lifestyles program for parents of preschool children. The Time2bHealthy Program offers a viable option for parental involvement in obesity prevention programs targeting young children. Given the online nature of the program it has the capacity to be utilised within metropolitan, regional and rural areas of Australia.