Obesity is difficult to reverse in older children and adults and calls have been made to implement obesity prevention strategies during the formative pre-school years. Childhood obesity experts suggest that prevention of overweight in the pre-school years should focus on parents, because parental beliefs, attitudes, perceptions and behaviours appear to contribute to children's development of excessive weight gain. While evidence suggests that parental variables may be instrumental in the development of obesity, there has been no systematic evaluation of whether intervening to change such variables will positively influence the development of excess adiposity during the pre-school years. This paper is a conceptual and methodological review of the literature on the parental variables targeted in interventions designed to modify risk factors for obesity by promoting healthy eating and/or physical activity and/or reducing sedentary behaviours in families of children aged 2–6 years. There were significant methodological limitations of existing studies and the scientific study of this area is in its infancy. However, the results suggest that the modification of parental variables known to be associated with obesity-promoting behaviours in pre-school children may show promise as an obesity prevention strategy; further research is needed.