Abdominal obesity is associated with risk of cardiovascular disease and type 2 diabetes mellitus. Waist circumference as a measure of obesity may be clinically useful as a predictor of metabolic syndrome in children. To develop age- and sex-specific reference values for waist circumference we evaluated the data obtained from Turkish children and adolescents. Waist circumference measurements from 4,770 healthy schoolchildren were obtained. Smoothed percentile curves were produced by the LMS method. The median curves of Turkish children were compared with four other countries: Australia, the UK, USA (Bogalusa) and Japan. Smoothed percentile curves and values for the 3rd, 5th, 10th, 25th, 50th, 75th, 85th, 90th, 95th and 97th percentiles were calculated for boys and girls. We found that waist circumference increased with age both in boys and girls. The 50th percentile waist circumference curve of Turkish children was over the British and Japanese but lower than the Bogalusa children and adolescents. This study presents data and smoothed percentile curves for waist circumference of healthy Turkish children aged 7-17 years. The differences in waist circumference of different countries can be explained by lifestyles and cultural characteristics. These data can be added to the existing international reference values for waist circumference of children and adolescents.