Adipose tissue is recognized as a key player in the regulation of whole body metabolism. Apelin, is a recently identified adipokine that when given to mice results in increases in skeletal muscle uncoupling protein 3 (UCP3) content. Similarly, acute apelin treatment has been shown to increase the activity of AMPK, a reputed mediator of skeletal muscle mitochondrial biogenesis. Given these findings we sought to determine the effects of apelin on skeletal muscle mitochondrial content. Male Wistar rats were given daily intraperitoneal injections of apelin-13 (100nmol/kg) for 2 weeks. We made the novel observation that the activities of citrate synthase, COX and HAD were increased in triceps but not heart and soleus muscles from apelin treated rats. Confirming these results we found that both nuclear and mitochondrial encoded subunits of the respiratory chain were increased in triceps from apelin treated rats. Similarly, apelin treatment increased the protein content of components of the mitochondrial import and assembly pathway. The increases in mitochondrial marker proteins were associated with increases in PGC-1 but not PGC-1 or PRC mRNA expression. Chronic and acute apelin treatment did not increase the protein content and/or phosphorylation status of AMPK and its downstream substrate ACC. These findings are the first to demonstrate that apelin treatment can induce skeletal muscle mitochondrial content. Given the lack of an effect of apelin on AMPK signaling and PGC-1 mRNA expression these results suggest that apelin increases skeletal muscle mitochondrial content through a mechanism that is distinct from that of more robust physiological stressors.