Primary objective: To investigate the association between reported past traumatic brain injury (TBI) and demographic, neuropsychiatric and criminographic parameters among individuals recently received into custody.

Research design: A random sample of men recently received into the New South Wales (Australia) criminal justice system were screened for a history of TBI and the details of up to five separate TBI episodes were obtained. We also screened for depression, psychosis, personality disorder, drug and alcohol use, and 'social connectedness'.

Main outcome and results: Among the 200 study participants, 82% reported past TBI. TBI was associated with a history of engagement in contact sports, school expulsion, daily illicit drug use, depression and psychosis.

Conclusions: Past TBI is common among prisoners entering the criminal justice system and, amongst other correlates, appears to be highly associated with increased rates of major mental illness.