This was a cross-sectional study of 1879 subjects (949 boys and 930 girls) to define the prevalence of overweight and obesity using three reference standards. The study involved affluent preschool children (2-5 years of age) from six creches, fifteen play-pen and three public schools of Amritsar city. Weight and height was obtained for each child and body mass index was calculated according to the formula weight (kg)/ height (m)². The prevalence of overweight and obesity was then determined using Centers for Disease Control and Prevention (CDC), International Obesity Task Force (IOTF) and World Health Organization (WHO) standards. All three methods gave different results. The present study revealed that WHO standards gave higher estimates of overweight and obesity while IOTF gave lower estimates. The level of agreement (k=0.94) between the WHO and CDC standards was higher. The prevalence of childhood obesity is dependent on the growth reference used.