PURPOSE To evaluate the role of the musculo-skeletal apparatus in patients with angina pectoris despite normal coronary angiograms. DESIGN A survey of patients and controls investigated by blinded observers. SETTING A tertiary cardiologic referral centre. SUBJECTS Thirty women and 18 men (mean age 52.9 years) with chest pain of an average duration of 3 years and 11 months were investigated. All had normal resting electrocardiograms. No patients showed evidence of left ventricular hypertrophy or valvular heart disease on echocardiography and all had a normal coronary angiogram. All had left ventricular ejection fraction > 50%, and none had signs of coronary vasospasm. Eighteen healthy persons (10 women and eight men, mean age 51.2 years) served as controls. MAIN OUTCOME MEASURES The group frequency of chest wall complaints, spinal radiograph and physical examination findings; pressure pain thresholds. RESULTS The patients had significantly more complaints of pain from the neck, chest, and thoracic spine, and sensations and pain radiating to the arms than the controls. The patients had more degenerative findings on radiograph than the controls, mainly at levels C4-C7. Physical examination showed that abnormal findings were significantly more frequent in patients than in the control group in the anterior and posterior chest wall, in the spine at levels Th1-Th6 and in the muscles of the neck and shoulder girdle. There were no statistically significant differences in pain thresholds or in neurological examination. CONCLUSION The musculo-skeletal abnormalities observed in the patients could include reflex mechanisms. Whether the abnormal findings are mainly responsible for the angina pectoris symptoms or merely epiphenomena warrants further study.