Background Weight-related peer-teasing is considered a potent prospective risk factor for development of disordered eating and clinical eating disorders. Currently, the interplay between genetic and environmental influences has yet to be elucidated. Aims To determine whether peer-teasing moderates latent genetic and/or environmental risk for disordered eating among female adolescent twins. Method Full quantitative gene-environment interplay modelling of longitudinal trajectory of disordered eating in 685 female twins from the Australian Twin Registry. Results A model permitting moderation of disordered eating by peer-teasing involving genetic and non-shared environment effects fit these data best. As levels of peer-teasing increased, both genetic and environmental influences on disordered eating strengthened; however, genetic sources increased proportionally more than environmental sources. Conclusions Weight-related peer-teasing represents a particularly powerful trigger for disordered eating. Nevertheless, it is amenable to intervention/prevention activities spanning individual to universal levels of endeavour.