Background: The origins of childhood obesity invariably need to be looked at within a family context and several reviews have concluded in favour of parental involvement in the treatment of paediatric obesity. However, there is little consensus on the format, and next to weight outcomes behavioural outcomes also merit more attention when assessing program effectiveness. Method: In this pilot study, a total of 50 families with overweight children (aged 6-12) were randomly allocated to a parent-led intervention group (cognitive behavioural training) or to a waiting list control group (Study 1). Afterwards, the parents of the waitlist control group also followed the intervention. All children were included in a follow-up study and were compared with a reference group (Study 2). Results: The intervention group as well as the waitlist group (who had not yet received treatment) showed a decrease in adjusted BMI over a 6-month period, although the decrease was only significant for the intervention group (Study 1). All children showed a decrease of 7% in adjusted BMI from pre to one-year follow-up measurement (Study 2), while the reference group showed an increase in adjusted BMI over that period. Parents reported significant positive changes in children's eating behaviour and a significant positive increase in familial health principles. Conclusions: Weight and behavioural outcomes suggest potential for intervention effectiveness. Long-term follow-up is needed to reveal residual benefits of enhanced parenting skills on environmental lifestyle changes.