Background: This study evaluates an individual, community-based treatment for obese children and their families. In this program, a treatment team applied solution-focused techniques to develop a custom-made treatment plan in collaboration with the participants. The treatment plan consisted of community-based lifestyle activities. Methods: 559 obese children with an average BMI z-score of 2.76 ± 0.54 took part in the 12-month study, and 372 children with an average BMI z-score of 2.75 ± 0.52 took part in the 24-month study. At the start of the study, ethnicity and special school needs were recorded. Before, after 12 months, and after 24 months of the treatment, body weight and height were measured. The effect of the treatment on body weight was evaluated using BMI z-scores. Results: 291 children (52%) completed 12 months of treatment, whereas 22 children (4%) were dismissed earlier due to a good response. After 12 months, the children showed a significant decrease in BMI z-score by 0.16 (95% confidence interval (CI) 0.11-0.20; p < 0.005). After 24 months, 103 children (28%) were participating in the program, with a significant decrease in BMI z-score of 0.15 (95% CI 0.07-0.22; p < 0.005). 50 children (13%) were dismissed before the end of the second year due to significant weight loss (standard deviation z-score reduction -0.38; 95% CI 0.30-0.46; p < 0.005; with an average treatment duration of 12.9 ± 6.4 months). There was a negative correlation of age and reduction in BMI z-score: children younger than 6 years showed a decrease in BMI z-score of 0.45 (95% CI 0.26-0.65) and 0.31 (95% CI 0.11-0.53) after 12 and after 24 months, respectively. Conclusions: Children showed a significant decrease in BMI z-score after the treatment. We found a negative correlation of age and weight loss. Special attention to patients with a high risk of drop-out might further improve these results. We advise a referral to obesity treatment as early as possible since a ‘wait and see' policy might have adverse results in obese children.