Adiponectin, a circulating adipose-derived hormone regulating inflammation and energy metabolism, has beneficial actions on cardiovascular disorders. Recent studies have suggested that adiponectin might be a potential molecular target for ischemic stroke therapy; however, little is known about the effects of adiponectin on traumatic brain injury. The present study examined the immunoactivity of adiponectin.Adult male Sprague-Dawley rats were subjected to lateral fluid percussion injury using the Dragonfly device. Immuno-histochemical studies showed that the adiponectin expression was increased in the cerebral cortex at 24 h after injury and in the hippocampus at 72 h after injury. Our findings suggest that adiponectin might participate in the pathophysiological process occurring after traumatic brain injury.