Background and Objective: Obesity has evolved into a present-day pandemic, impacting individuals of all ages globally. Various factors have been implicated in the worldwide increase of obesity and diseases related to it, examined from numerous viewpoints. Environmental obesogen is characterized as a chemical agent that promotes obesity in humans or animals. This review offers an up-to-date synopsis of findings from both animal and human research concerning the contribution of environmental obesogens to obesity, as well as a detailed perspective on the mechanisms by which they exert their effects. Methods: The review was created by searching Pubmed and Google Scholar, using many keywords, such as: “Obesity", “Obesogens", “obesogenic compounds", “Endocrine-disrupting chemicals", “mechanism of action", “in vivo model", “in vitro model", “PPARγ". Results: Several mechanisms have been proposed to explain the mechanism of action of obesogens, including activation of PPARγ, altering the gut microbiome, altering appetite, satiety and food preferences, DNA methylation, regulatory role of micro-RNAs, impaired thermogenesis. In vivo and in vitro studies have provided evidence of the effects of obesogenes and have proposed additional mechanisms to explain their mechanism of action. Conclusions: Although great progress has been made, studies about obesogens are still in the early stages, and more research is needed to discover the obesogens that are still unknown, and to understand the precise mechanisms of the previously discovered obesogens.