Lipid homeostasis requires a strict balance between lipid intake and consumption. This balance is controlled by different systems that regulate food intake, energy storage and energy expenditure. This review focuses on the roles of peroxisome proliferator- activated receptors (PPARs) in some of these regulatory processes. PPARs are transcription factors that bind and are activated by fatty acids and fatty acid derivatives. They act as lipid sensors and adapt the metabolism and development of various tissues to lipid availability. Due to their actions on lipid metabolism, PPARs are bona fide therapeutic targets in the treatment of metabolic syndrome not only by affecting gene expression patterns in several tissues but also by inducing remodeling of tissues such as adipose or skeletal muscle.