[en] The Royal Decree 1566/1998 of July 17th establishes the criteria on quality in radiation therapy and is a cornerstone in Spanish regulation of this medical field. The Royal Decree gives some rules that, from a medical point of view, are considered as a good practice. Radiation protection of patients is necessary to achieve a high quality radiation oncology treatments. That is the reason why Royal decree 1566/1998 is titled 'quality criteria in radiation therapy'. A quality control program must be tailored to every single radiation oncology department and, for this reason, its standardization is difficult. Nevertheless, some medical procedures are defined by the royal decree and such procedures are the minimum criteria that all the departments must follow in the development of its own quality control program. The authors make some reflections about health regulations about radiation oncology in Spain, pointing out that a legislative dilemma between radiation protection and treatment of cancer due to application of the legislative rules may occur. The social and medical cost of rigid bureaucratic procedures is pointed out. A large amount of equipment controls and measurements takes time that could be used in treating patients. This is more important in an environment of limited technical and human resources. (author)