Objective Investigate effectiveness of a 5-session manualized intervention for addressing needs of caregivers of persons in acute traumatic brain injury (TBI) rehabilitation. Design Prospective, pilot randomized controlled trial. Setting Inpatient brain injury rehabilitation unit, level 1 trauma center. Participants Patients (N=93) with moderate-to-severe TBI and their family members were enrolled in the study with 42 randomized to the treatment group, 51 to the control group. Intervention Five-session manualized caregiver intervention with educational, stress and anxiety self-management, coping, and emotional support components. Main Outcome Measures Family Needs Questionnaire-Revised, knowledge assessment, Zarit Family Burden Scale, and Brief Symptom Inventory-18 were collected at pretreatment, posttreatment, and 3-month follow-up. Results Treatment group caregivers showed an increase in met needs for emotional, instrumental, and professional support, and brain injury knowledge from baseline to posttreatment, whereas controls did not. Between-group differences were significant for only emotional support needs. Treatment effects were not sustained at 3-month follow-up. Conclusions Caregivers of persons undergoing acute TBI rehabilitation may benefit from interventions that target their unique needs. Caregivers may require additional and longer-term supports to sustain treatment benefits.