Abstract Background: Fibromyalgia is a disabling disease. One of the characteristics of FM is the absence of swelling associated with the pain. The other is the existence of tender points. A deep understanding of what is this painful and debilitating condition is therefore essential. Objective: to characterize the pain in patients with fibromyalgia. To realize the impact this pain has on the lives of patients who suffer from fibromyalgia. Material and method: It is a descriptive correlational study. The sample consists of 221 individuals, 4 males and 217 female(98,2%). Hypothesis: The perception of pain intensity, the way pain manifests itself, the evolution of pain intensity and widespread pain index influence FM patients. The instruments used were the Visual Analogue Scale for pain (VAS), the Manifestation of Pain and the Generalized Pain Index questionnaire. Results: The sample is mostly formed by females (98.2%), with an average age of about 45 (± 10,587), who live in urban areas (79.6%), who are married or living with a partner (71.9%), are living with relatives or others (89.1%), have completed secondary education (49.3%) and are currently employed (42.1%). Pain intensity displayed by fibromyalgia patients has an average value of 7.59, the Generalized Pain Index shows an average value of 11.84. The intensity of pain perception and the manifestation of pain condition the way a patient with FM will be able to live. Conclusion: The intensity of perceived pain by this study patients is, on VAS’s average ratings, equal to 7.59. Most subjects with FM reported moderate or severe pain.The Generalized Pain Index has an average value of 11.84, the majority of these individuals feel pain in approximately 12 to 19 corporal regions and their pain is long-lasting. ; info:eu-repo/semantics/publishedVersion