Our studies have focused on metabolic effects and mechanisms of action of adiponectin in skeletal muscle, including direct metabolic effects and regulation of insulin sensitivity. Most recently, we performed a comprehensive unbiased metabolomic analysis of skeletal muscle from adiponectin knockout mice after high fat diet (HFD) feeding, and investigated the ability of adiponectin replenishment to correct HFD-induced changes. Hyperinsulinemiceuglycemic clamp studies showed adiponectin administration corrected HFD-induced defects in basal/post-insulin rate of glucose disposal (Rd) and insulin signaling in skeletal muscle. Metabolomic profiling of skeletal muscle indicated that changes in various ceramide species, triacylglycerol and diacylglycerol species, branched chain amino acids, glycerolipids, fatty acids, pentose phosphate pathway and various lysolipids were detected and will be discussed here. Overall, our data revealed a key signature of relatively normalized metabolism across multiple metabolic pathways with adiponectin supplementation under the HFD condition. Analysis of muscle mitochondrial structure and function also indicated that adiponectin treatment corrected HFD-induced pathological changes. We suggest that adiponectin is a major orchestrator of skeletal muscle metabolism with effects on lipoprotein lipase, transport and oxidation of fatty acids. Glucose metabolism is also regulated via insulin-independent and insulin-sensitizing effects. Evidence that AdipoRs and APPL1 play important roles in mediating the metabolic effects of adiponectin will be discussed. In summary, this presentation will include data from unbiased comprehensive metabolomic profile of skeletal muscle from AdKO mice subjected to HFD ± adiponectin and relate these to changes in whole body glucose handling, insulin signaling and mitochondrial structure and function. The mechanisms of action of adiponectin will also be discussed.