This study investigated the changes in coping styles of patients with acquired brain injury who underwent cognitive rehabilitation, and the effects of these changes on their quality of life. Participants were 110 patients in the chronic phase post-injury, who underwent outpatient cognitive rehabilitation according to current guidelines and standards. Coping style (Utrecht Coping List) was measured at the start of rehabilitation (T0) and repeated at least 5 months later (T1). Coping style was related to quality of life measured at T1 (Life Satisfaction Questionnaire and Stroke-Adapted Sickness Impact Profile). Results indicated that active problem-focused coping styles decreased and passive emotion-focused coping styles increased significantly between T0 and T1. Furthermore, the study showed that increases in active problem-focused coping styles and decreases in passive emotion-focused coping styles predicted a higher quality of life in the long term. These changes in coping styles are adaptive for the adjustment process in the chronic phase post-injury. Overall however, most participants showed maladaptive changes in coping styles. Implications for cognitive rehabilitation are therefore discussed.