A 64-year-old man with TBI was admitted to our institute. In following days, he showed unusual behavior of agitation, restlessness, emotional instability and inattention. Post-traumatic delirium was tentatively diagnosed, and donepezil was given for his cognitive dysfunction. Although there was partial relief of agitation, he sustained back pain despite medication. Lumbar magnetic resonance image revealed SDH along the whole lumbar spine, and surgical drainage was followed. Postoperatively, his agitation disappeared and further medication was discontinued. We report a unique case of post-traumatic delirium in a patient with concomitant TBI and spinal subdural hemorrhage (SDH) that resolved with operative drainage of spinal hemorrhage.