Chronic pelvic pain is difficult to diagnose and usually has a poor outcome. However, if it was identified early it might have a better prognosis. We treated three patients whose trigger points in obturator internus were diagnosed as origin of myofascial pain. The first patient complained of coccygodynia with pain that radiated up his left leg when walking. The second patient had coccygeal pain that radiated to the left thigh area. The last patient was troubled with coccygeal and pelvic pain at anytime. In all of the cases MRI studies of the lumbar spine and pelvis were unrevealing. Electrodiagnostic studies were normal. The impression was that the patients had the myofascial pain syndrome, therefore injections with local anesthetics and cortisone at the myofascial pain originated in obturator internus. Although each of the patients had different symptoms, they all had a good response to treatment. (J Korean Acad Rehab Med 2009; 33: 131-134)
