Post traumatic stress disorder (PTSD) and other reactions including driving phobias and depression have in recent years been clearly identified as common motor vehicle accident (MVA) sequelae. To date, no treatment outcome data exist for PTSD following MVA beyond case study reports and one pilot investigation. The present study reports on the first randomized control trial for PTSD following MVA. Twenty volunteer participants who had motor vehicle accidents resulting in physical injury requiring medical attention and PTSD were recruited through rehabilitation service providers, other psychologists, community physicians, and lawyers. Assessments included a structured interview for diagnosis of post traumatic stress disorder (Clinician Administered PTSD Scale) by an independent rater, a range of self-report symptom questionnaires and a behavioural test wherein they had their heart rate and subjective distress measured in reaction to idiosyncratic audio descriptions of their accident. Participants were randomly assigned to eight to ten hours of individual cognitive-behavioural therapy (n=10) or to a wait list control group (n=10). Treatment included education about post-trauma reactions, relaxation training, exposure therapy with cognitive restructuring and instruction for self-directed graduated behaviour practice. Results demonstrated statistically and clinically significant treatment effects across structured interviews, self-report questionnaires and the behavioural test. Treatment gains were maintained over a 6 month follow-up using self-report questionnaires.