Objective: To determine the prevalence and characteristics of shoulder pain in people with traumatic brain injury participating in inpatient rehabilitation and to compare the clinical presentation with that of people with stroke. Design: A prospective comparative study. Setting: Six metropolitan rehabilitation units. Subjects: Eighty-seven people with traumatic brain injury and 52 people with stroke took part in the study. Main measures: Assessment of shoulder pain, range of motion, strength and function was conducted on admission and, for the subjects with traumatic brain injury, at discharge if rehabilitation exceeded two weeks. Results: The prevalence of shoulder pain in people with traumatic brain injury was 62%, which was comparable with the 69% of subjects with stroke that experienced shoulder pain (odds ratio 0.72, 95% confidence interval 0.34-1.5). Fracture in the shoulder complex and passive shoulder external rotation range of motion were the best predictors for shoulder pain after traumatic brain injury. This was different from the subjects with stroke for which the best predictors were passive shoulder flexion range of motion and length of acute hospital stay. Conclusion: There is a relatively high prevalence of shoulder pain after traumatic brain injury. Trauma to the shoulder complex contributes to shoulder pain after traumatic brain injury, making clinical presentation different from people with stroke. The findings support the need for greater attention in the management of shoulder pain after traumatic brain injury.