Changes in physical activity with the aim of increasing energy expenditure are usually an important component of childhood obesity treatment. Physical activity also has several other aspects that are positive for the obese child's health, such as improving the metabolic profile and psychological well being. The aim of this paper is to give a short review of what we know about physical activity in paediatric obesity treatment. In addition, practical recommendations will be presented which a health care provider can suggest to obese children and their families with a special focus on daily activity, participation in physical education classes and sports, sedentary behaviours, active commuting to school and how to get family and friends involved in supporting the child.