The Quality Handbook includes the description of the activities carried out in Radiotherapy and the methodology used to ensure the Quality Assurance according to the principles indicated in national and international documents of reference and the recommendations of accreditation agencies. The structure of the Quality Handbook, the main aspects of single chapters, the selected quality indicators undergoing inspections are analysed and procedures to be followed for changes and updating of the Quality Handbook are described. The Quality Assurance program is illustrated in another article of this issue.