To help fibromyalgia syndrome's diagnosis, the authors propose the use of Back Pain Classification Scale (BPCS), verbal test for pain analysis, able to distinguish between organic and functional disease. Two-hundred patients suspected for fibromyalgia and forty controls completed the questionnaire and so it was possible correctly to distinguish patients with organic disease from those affected by fibromyalgia. The authors conclude that BPCS can represent a useful tool for fibromyalgia diagnosis.