This research was conducted to assess the effect of a weight management program in Turkish school children with overweight and obesity. Forty one students formed the intervention group while 40 students formed the control group in two elementary schools. Students in intervention group were given seven training sessions in a period of 2.5 months. Concurrently, parents were given two trainings and consultancy. The Body Mass Indices (BMIs) of the intervention group at the third measurement were decreased (p < .05) significantly when compared to the control group. The findings suggest use of school-based weight management programs starting from elementary school.