Chronic widespread pain (CWP) is very prevalent in the general population (5%-10%) and is characterized by pain in all four body quadrants, the neck, and back. CWP differs from localized pain not only in its distribution but also in the way it affects lives. Multiple pain sites are associated with higher pain intensity, longer pain duration, and greater disability. Anxiety and depression are more common in CWP patients than among those with localized pain and pain-free controls. Fibromyalgia (FM) has been classified as CWP of more than a 3-month duration, with mechanical hyperalgesia at > or = 11 tender-point sites. FM has been found in 2% to 4% of community subjects and represents the extreme of CWP. This article compares pain characteristics, quality of life, consequences for daily living, and psychosocial status between FM patients and individuals with CWP. Available evidence shows that FM is associated with more severe symptoms and consequences for daily life and higher pain-severity compared with CWP.