Introduction Cancer is a severe and acute life-threatening disease with long-term multimodal treatments. Adolescent and young adult (AYA) with cancer are in a vulnerable phase in life, experiencing psychological stress both as an individual and family. Thus, it is necessary to raise awareness to the young patient special psychosocial needs and to increase their psychological outcomes and quality of life. The aim was to develop an evidencebased guideline to ensure a comprehensive and structured psychosocial follow-up throughout the cancer trajectory. Methods The guideline development group consisted of amultidisciplinary teamof health providers and three AYA patient representatives. A systematic literature search was made to identify the evidence. Relevant literature was read and critically evaluated by using checklists from The Critical Appraisals Skills Program. The findings were discussed with stakeholders before making recommendations from the evidence. Finally, the draft was sent to clinicians for comments that were processed before the guideline was completed Results The work resulted in a clinical guideline consisting of seven documents: 1. Psychosocial support for AYA patients with cancer 2. Checklists with interventions for each stage of the patient pathway 3. Interdisciplinary meetings 4. Network Meetings and supervisory group 5. Communication with young patients 6. Rights and support for AYA patients 7. Rehabilitation plan Conclusions Based on the evidence we recommend that clinicians use the clinical guideline in a structured manner. We hope that the guideline will improve the psychological outcomes for the AYAs and their families.