During puberty, rapid, complex hormonal, physical and cognitive changes occur that affect body image and eating behavior. The aim of this cross-sectional study, a secondary analysis of data from the Greek Healthy Growth Study, was to explore associations of disordered eating behaviors and body image in 1206 10–12-year-old girls during pubertal maturation, with serum leptin and adiponectin levels, according to body mass index (BMI). Eating behavior and disordered eating were assessed with the Dutch Eating Behavior Questionnaire (DEBQ) and the Children Eating Attitudes Test Questionnaire (ChEAT), respectively. Associations of components of DEBQ and ChEAT with maturation according to Tanner Stage (TS) and levels of leptin and adiponectin were explored by univariate and multivariate regression analysis. Adiponectin levels in girls at TS 1 were positively associated with the “social pressure to eat” score of ChEAT. Leptin levels in girls at TS 4 were positively correlated with the “restraint eating” score of DEBQ, and the “dieting”, “body image” and “food awareness” scores of ChEAT. After adjustment for TS and BMI, only “body image” and leptin remained significant. Further research may shed light on how these hormonal changes affect eating behaviors at various pubertal stages, contributing to “TS-specific” preventive strategies for eating disorders in girls.