The objective of this systematic review is to provide a qualitative comparison of interactive electronic media interventions for the prevention or treatment of obesity and/or obesity-related behaviours in children and adolescents. Literature searches of 12 databases from the earliest publication date until March 2010 were conducted. Twenty-four studies in which children and/or adolescents interacted with electronic interventions delivered as adjunct or sole interventions for the prevention or treatment of obesity and/or obesity-related behaviours met the inclusion criteria. Fifteen focussed on obesity prevention and nine on treatment interventions. The average study quality design score was 45%. Most studies demonstrated some form of significant outcome (e.g. reported changes in dietary and/or physical activity behaviours) in participants receiving interactive electronic interventions, with 11 out of 15 studies leading to positive changes in measured or reported adiposity outcomes. In 87% of studies, the effects of interactive electronic interventions were not separately evaluated from other intervention components. These results should be viewed with caution because of the overall poor quality of the studies. Studies were mostly conducted in the USA, largely in minority populations, and the direct transferability of interventions to other populations is unclear. Further high quality research is needed in this area to accurately inform the evidence base.