Purpose To develop an evidence-based decision aid for parents of children with cancer and to help guide them in the use of complementary and alternative medicine (CAM) for cancer care. Methods This study had a mixed research design. The needs of parents were investigated by survey and focus group. A systematic review and meta-analysis were performed on the effectiveness of CAM using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Clinical experts were interviewed and a decision aid on CAM treatment for pain was developed. Results Parents emphasized the importance of reliable information on CAM, focusing primarily on communication and a broad spectrum of complaints related to cancer treatment. The decision aid on CAM for pain included five modalities based on 11 randomized control trials (RCTs): hypnotherapy, mind-body techniques, massage, healing touch, and music therapy. Meta-analysis could be performed on hypnotherapy, which significantly reduced cancer-related procedural pain compared with standard care (MD, − 1.37; 95% CI, − 1.60, − 1.15; P