A volunteer sample of 22 participants with chronic traumatic brain injury (TBI) (onset >1 year) and relative hemiplegia that revealed moderate disability in the more-affected upper limb (UL) participated. Constraint-induced (CI) movement therapy (CI therapy) was employed for a 2-week period; treatments included massed practice, shaping of the more-affected UL, behavioral contracts, and other behavioral techniques for affecting transfer to a real-world setting. We used the Wolf Motor Function Test, the Fugl-Meyer Motor Performance Assessment, and the Motor Activity Log to measure outcomes. All outcome measures improved significantly as a result of the intervention. More-adherent participants had more improvement compared with less-adherent participants. These preliminary results suggest that CI therapy may be effective for improving UL motor function following chronic TBI.