BACKGROUND: Childhood obesity has reached epidemic levels. Children obesity predisposes them to risk of cardiac disease in adulthood. Environmental factors, lifestyle preferences, and cultural environment play pivotal roles in the rising prevalence of obesity worldwide. Furthermore, family life style has a great influence on children obesity. This study aimed to determine the effect of family-oriented weight reduction program on the children’s anthropometric measurements.    METHODS: This was a non-pharmacological clinical trial study which was performed on 4-18 years old children attending outpatient clinics of Isfahan Endocrine and Metabolism. Anthropometric measurements were recorded for all the participants. Children took part in one educational session in which they were taught about ways and benefits of having a regular physical activity each day and also benefits of having healthy nutrition. All the participants took part in every 4 months one-hour educational sessions and their anthropometrics were measured.    RESULTS: Fifty eight single-mother families participated in this study. Fourteen single-father families started the intervention but did not follow it to the end. Children’s body mass index (BMI) z-score decreased significantly after the study. Children waist circumference (WC) and hip circumference (HC) significantly increased. Mothers WC and waist to hip ratio (WHR) increased significantly. Regression test showed that mother BMI was an independent factor (B = 0.307; P < 0.021). The effect of the pattern of children’s BMI changed across a one-year period.    CONCLUSION: Our study showed significant effect of repetitive family life style education on children’s BMI z-score changes. Family, as the first place for children behavior formation, must be regarded as one of the best place to tackle childhood obesity.       Keywords: Children Obesity, Parents, Life Style Intervention, Education, Anthropometric Indices