The aim was to develop and validate an instrument to measure the body size perception and body dissatisfaction among preschoolers. The Preschoolers Body Scale (PBS) is composed of two sets of four figures (male and female versions) in front and profile views, representing four weight categories. The scale was administered to a total of 244 preschoolers aged 4 to 6.4 years, 42 participated in the pilot study and 202 took part in the instrument’s reliability study. Also, 10 expert pediatricians aged 50 to 65 years participated in the validation and reliability process. Results revealed good validity and moderateto-high reliability, which improved as children became older. We conclude that the PBS is a reliable and appropriate instrument to measure body perception in preschoolers, particularly among participants older than 5 years.