Childhood obesity is increasing in epidemic proportions worldwide. Morbidity related to obesity is associated with the degree of body fat mass (FM) and direct measurement of it would be the best way making the diagnosis. However, due to practical difficulties surrogate markers have been used and most popular are the BMI and waist circumference (WC). Although none of them are specific, they could be used to obtain a reasonable assessment. However, the reliability of these measures depends to a greater extend on the cutoff values used. International cutoffs are mainly based on white Caucasian studies and its usefulness in other ethnic groups are doubtful. There is a clear ethnic differences in body composition, where Asian populations have more fat in the body to any given BMI compared to white Caucasian populations. Because of that even WHO has suggested to have lower BMI cutoff values for Asian populations while IDF has used a lower waist circumference cutoff to diagnose metabolic syndrome in Asian populations. Although there is no universal consensus in drawing up of ethnic/population specific anthropometric cutoff values, in the published literature there are cutoff values derived for such groups for both adults and children. It is interesting to assess the suitability of newly developed Sri Lankan anthropometric cutoff values in the diagnosis of obesity in Sri Lankan children.