Mild traumatic brain injury (TBI) is the most common form of TBI. Most people recover after mild TBI, but a small percentage continues to have persistent problems, predominantly depression. There is, however, minimal literature on the risk factors associated with mild TBI depression. In a sample of 43 mild TBI patients, followed longitudinally for 1 year, the prevalence of new-onset depression was found to be 18%. Older age and presence of frontal subdural hemorrhage were the only two significant findings noted in the depressed group compared with the nondepressed group. Identifying risk factors for mild TBI depression can aid in early diagnosis and treatment.