In the medical literature, there are only a few references on refractory fibromyalgia and there is no consensus definition available on this concept. Some definitions of refractory fibromyalgia have been proposed based on the lack of response to a number of medications, and perhaps the most appropriate term is treatment-refractory fibromyalgia. To achieve the definition of treatment-refractory fibromyalgia, it is necessary to consider several previous steps, such as making sure the diagnosis has been made properly and a differential diagnosis with entities that can mimic fibromyalgia symptoms (including complete physical examination and laboratory test) has been made. The possibility that another factor that alters the response to treatment should be investigated, and in particular review all prescribed medication and search for some non-medical reasons that could mask the response to treatment (e.g., legal compensation). The definition of refractory fibromyalgia is complex and probably should include a lack of response to a specified number of drugs or to combination therapy with at least two non-pharmacological measures. In this article, it is not our purpose to present a formal definition, but to raise the possible bases for this purpose. We believe that it is a subject that must be discussed extensively before reaching a consensus definition. Key Points • There is no appropriate definition to classify fibromyalgia patients who do not respond to the usual pharmacological and non-pharmacological measures according to the national or international guidelines. • A consensus definition is required to classify these patients, which could help standardize future management strategies. In this article, we propose the bases on which refractory fibromyalgia could be defined.