CONTEXT: The "Standards, Options and Recommendations" (SOR) project, which started in 1993, is a collaboration between the French Federation of Cancer Centers (FNCLCC), the 20 French Regional 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 the outcome of cancer patients. OBJECTIVE: To update clinical practice guidelines for the assessment of pain in adult or children with cancer in collaboration with the French society for pain study and treatment. METHOD: The methodology is based on a literature review and critical appraisal by a multidisciplinary group of experts who define the CPGs according to the definitions of the Standards, Options and Recommendations project. Once the guideline has been defined, the document is submitted for review by independent reviewers. RESULTS: This article is a summary version of the full document presenting the clinical practice guidelines with algorithms. The main recommendations concern the means used to evaluate pain and its consequences and their use in specific cases (acute or chronic pain, patients able to communicate or not, children under or over 6 years old). Others recommendations were also established concerning the evaluation ofpsychological, social and family context, the evaluation of pain in hospital or at home, in terminal phase patients and for the establishment of a therapeutic strategy and follow-up of patient with pain.