Alcohol and drug use at the time of injury have been strongly implicated as causal factors of spinal cord injury (SCI) and traumatic brain injury (TBI). Researchers have only begun their efforts to investigate the pre-injury incidence of substance abuse in an effort to identify persons at risk for traumatic injury. No studies have compared brain and spinal cord injury populations. This investigation was based in an urban, level one trauma center federally designated as a model system of comprehensive rehabilitative services for persons with TBI and persons with SCI. Pre-injury patterns of alcohol and illicit drug use were compared among patients with SCI and patients with TBI, matched for age, gender, race, and mechanism of injury (n= 52). In accordance with previous research, participants were primarily young, unmarried, males with at least a high school education. Eighty-one percent of patients with TBI and 96% of patients with SCI reported pre-injury alcohol use. The rate of pre-injury heavy drinking for both groups was alarmingly high. Fifty-seven percent of persons with SCI and 42% of persons with TBI were heavy drinkers. Implications for risk identification, treatment, and future research are discussed.