In the unique situation of siblings of chronically ill children or children with disabilities, prevention courses should reduce negative effects like additional stress and help to maintain quality of life. For their further development, resources and stress management strategies should be investigated as possible predictors of quality of life changes. Self-esteem and problem-solving coping strategies had a particular influence. Resources and stress management strategies significantly predicted quality of life. Therefore, the strengthening of resources and positive stress management strategies should remain to have a significant role in prevention work.