The worrying increase of nutritional disorders and psychological discomfort in young population, mainly from western societies, shows that body image could be a basic variable in a population screening especially during growth when physical changes and biological and emotional development occur. This is one of the first studies in northern Italy investigating differences in body shape concerns among different age-groups and sexes. The sample consisted of 1754 Italian youths aged 11-23 years. Participants were examined during a cross-sectional study. Body image perception was assessed using appropriate Body Silhouette Charts. Body Mass Index was calculated from measured height and weight. The results demonstrated age variability and sexual dimorphism in body image perception. The analysis of body image perception is a valid source of information and should be assessed in studies on youth growth, since it varies with age, sex, population, pathologies and socio-cultural environment.