FiRST (Fibromyalgia Rapid Screening Tool) is a brief questionnaire comprised of six "yes/no" questions for the detection of fibromyalgia syndrome. For clinical use, however, it requires further validation among various chronic pain syndromes. After authorized translation into Japanese and acquiring FiRST authorization for academic use, we used the Japanese FiRST in our chronic pain outpatients as questionnaires. The FiRST questionnaire was used to assess 71 patients with chronic pain resulting from fibromyalgia (n=11), and the results were compared with other chronic pain patients (n= 60). A cut-off score of 5 (the number of positive items) revealed the identification of fibromyalgia patients with a sensitivity of 100% and a specificity of 74.4%. Each of the six questions revealed a significant difference (Fisher test) in comparisons between fibromyalgia and the other chronic pain syndromes group. In conclusion, FiRST is a simple questionnaire with excellent discriminative value in daily practice, comprehensively delineating fibromyalgia.