Although, the dinitrophenols and other related compounds are deeply poisonous, they are still used as pesticides, drugs or even weight loss agents. Today, DNP is used by bodybuilders, often illegally, to rapidly lose body fat before contests. It is thought that they uncouple the oxidative phosphorylation by carrying protons across the mitochondrial membrane, leading to a rapid consumption of energy without generation of ATP. Therefore, in this paper we review the toxicological aspects of dinitrophenols derivatives.