Myofascial pain syndrome is very common disease but cause symptoms that are easily misdiagnosed as other conditions. The authors report a case of chest pain caused by the trigger points in the scalenus muscle. A 43 year-old man had chest pain without any history of trauma or infection. And, there were not any abnormal findings by cardiology and pulmonary evaluation. On physical examination, the scalenus muscle had the trigger points, and the chest pain was successfully treated by trigger point injections.