Psychiatric disorders are common and often debilitating following traumatic brain injury (TBI). However, there is little consensus within the literature regarding the risk factors for post-injury psychiatric disorders. A 1-year prospective study was conducted to examine which pre-injury, injury-related, and concurrent factors were associated with experiencing a psychiatric disorder, diagnosed using the Structured Clinical Interview for DSM-IV-TR Axis I Disorders, at 1 year post-injury. Participants were 122 adults with TBI and 88 proxy informants. Psychiatric disorders were common both pre-injury (54.1%) and at 12 months post-injury (45.9%). Results of regression analyses indicated individuals without a pre-injury psychiatric disorder or psychiatric symptomatology in the acute post-injury period were less likely to have a psychiatric disorder at 12 months post-injury. These findings confirm the importance of pre-injury history for the prediction of post-injury psychiatric disorders. Limb injury also emerged as a useful early indicator of later psychiatric disorder. Post-injury psychiatric disorders were associated with concurrent unemployment, pain, poor quality of life, and use of unproductive coping skills. The clinical implications of these findings are discussed.