Context. The "Standards, Options and Recommendations" (SOR) project, started in 1993, is a collaboration between the Federation of the French Cancer Centers (FNCLCC), the 20 French comprehensive Cancer Centers and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcome for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary group of experts, with feedback from specialists in cancer care delivery. Objectives. To identify consequences in terms of liability of the development of SOR guidelines and to formulate recommendations for the FNCLCC and medical doctors using SOR. Methods. Data have been identified by literature search on legal matters by CNEH's Legal Center JuriSanté, then submitted to a group of 8 experts. Results. The main conclusions of the present study are: 1)The SOR attest a high level of quality and methodological rigor; 2) according to legal considerations and in comparison to the available scientific data, the SOR guidelines can be considered as the state of the art in oncology at time of release; 3) the study identified six quality properties of Standards, Options and Recommendations (SOR): information contained in the SOR must be serious, accurate, reliable, complete, up-to-date and secure. The respect of these quality criteria is essential in the matter of liability; 4) when gathered, they can prevent the actors from being implicated on questions of liability. Specialists who use the SOR may avoid problems of liability, nevertheless evidence and the state of the art may evolve with time; 5) clinicians who do not use the SOR, may appear to be responsible for disasters, except if they can justify their medical decision (evolution of scientific knowledge or specific clinical circumstances, etc.); 6) therefore, SOR developers need to keep in mind these essential properties when SOR are prepared; 7) the SOR steering committee (COSOR) analysed the conclusions of the present legal study and defined a series of actions and procedures to guarantee the respect of the above quality criteria.