To evaluate the efficacy of adapted cognitive behavioral therapy (CBT) for sleep disturbance and fatigue in individuals with traumatic brain injury (TBI).Parallel 2-group randomized controlled trial.Outpatient therapy.Adults (N=24) with history of TBI and clinically significant sleep and/or fatigue complaints were randomly allocated to an 8-session adapted CBT intervention or a treatment as usual (TAU) condition.Cognitive behavior therapy.The primary outcome was the Pittsburgh Sleep Quality Index (PSQI) posttreatment and at 2-month follow-up. Secondary measures included the Insomnia Severity Index, Fatigue Severity Scale, Brief Fatigue Inventory (BFI), Epworth Sleepiness Scale, and Hospital Anxiety and Depression Scale.At follow-up, CBT recipients reported better sleep quality than those receiving TAU (PSQI mean difference, 4.85; 95% confidence interval [CI], 2.56-7.14). Daily fatigue levels were significantly reduced in the CBT group (BFI difference, 1.54; 95% CI, 0.66-2.42). Secondary improvements were significant for depression. Large within-group effect sizes were evident across measures (Hedges g=1.14-1.93), with maintenance of gains 2 months after therapy cessation.Adapted CBT produced greater and sustained improvements in sleep, daily fatigue levels, and depression compared with TAU. These pilot findings suggest that CBT is a promising treatment for sleep disturbance and fatigue after TBI.