The aim of this nationwide survey was to explore, based on an open-ended question, cancer-bereaved siblings’ advice to peers with a brother or sister with cancer. Half of the advice related to being with the ill sibling and cherishing the time together. Other advice related to the value of communicating about the situation, letting go of guilt, and living life as usual. The results highlight the importance of health care professionals, family, and others facilitating for siblings to spend time together and communicate openly.