The purpose of this study was to determine the percentiles of interpopliteal distance to diagnose bowleg in 0-6 year-old children. Measurement of interpopliteal distance is a simple but valuable indicator in clinical examination to diagnose bowleg. We analyzed data from the anthropometry of Turkish children aged 0-6 years. The primary sampling unit included 21 family health centers (Aile Sagligi Merkezi) located in the city center and suburbs of Kayseri, Turkey. A total of 2,873 children and adolescents (1,419 boys, 1,454 girls), whose parents gave consent were included in the study. The smoothed percentiles and Z-scores were calculated by age and gender in 0-6 year-old children in quarter year intervals except for the 0-28-day newborn period. We found a significant correlation (r: 0.60, p < 0.001) between body weight and interpopliteal distance (after onset of walking). We consider that percentiles of interpopliteal distance can be used in the follow-up of children who may be at risk of bone and growth disorders. The zone between -2 standard deviation (SD) and +2SD values can be used to decide if the child has a normal growth pattern.