The neurophysiologic term allodynia has been applied to fibromyalgia because people with that disorder experience pain from pressure stimuli which are not normally painful. The nociceptive neurotransmitters of animal studies are now relevant to this human model of chronic, widespread pain. Evidence is presented to implicate several chemical pain mediators (including serotonin, substance P, nerve growth factor, and dynorphin A) in the pathogenesis of fibromyalgia. This perception is hopeful because it offers many new options for the development of innovative therapy.