Objective: To examine the relationship between balance, attention, and dual-task performance in persons with acquired brain injury. Design: Cross-sectional study. Setting: Rehabilitation center and supported living program. Participants: 24 subjects aged 18 to 58 years (mean, 39y) with acquired brain injury able to ambulate 12m (40ft) with (29%) or without an assistive device. 58% were independent community ambulators. 54% had fallen in the past 6 months; 42% reported unsteadiness with standing or walking. Interventions: Participants completed a battery of balance, attention, and dual-task assessments. Main Outcome Measures: For balance, the Berg Balance Scale (BBS), Four Square Step Test (FSST), and High Level Mobility Assessment Test (HIMAT); for attention, the Symbol Digit Modalities Test (SDMT), Moss Attention Rating Scale (MARS), modified for a single test session, and a walking dual-task assessment. Results: The BBS mean score was 46/56, the FSST mean score was 19.7 seconds, the HIMAT mean score was 20/54, the SDMT mean score was 30 correct, and the MARS mean score was 79. Dual-task costs were observed with variable patterns across subjects: 48% demonstrated primarily motor slowing, 9% had reduced cognitive accuracy without motor slowing, and 35% demonstrated decrements in both tasks. Subjects with a falls history had more impaired balance (HIMAT, BBS, FSST, all P<.026), but did not differ significantly in dual-task performance or attention. Conclusions: Our test battery matched the range of motor and cognitive abilities of the sample. Balance was more strongly related to falls history than measures of attention or dual-task performance. Injury chronicity may have allowed some subjects to develop strategies to optimize dual-task performance. Alternatively, motor slowing in dual-task conditions may be an adaptive strategy, allowing performance of multiple tasks with reduced safety risk. Further investigation in this area is warranted to devise intervention strategies for reducing falls risk after brain injury.