Cardiokymography is a technique to assess myocardial wall motion by means of an electromagnetic field induced over the left precordium. The normal cardiokymogram (CKG) is characterized predominantly by systolic inward movement. An abnormal contraction pattern--either at rest or provoked by a stress test--reveals a different tracing with decreased or absent systolic inward motion and/or systolic outward motion (bulging). In 50 patients with suspected coronary artery disease (CAD) the CKG was recorded before and after treadmill exercise test and the results compared to coronary angiography. Out of 33 patients with angiographically documented CAD (more than 50% luminal narrowing) 25 showed an abnormal CKG after exercise. There was one false positive postexercise CKG in the group of 17 patients without angiographically documented CAD. The CKG allows the qualitative assessment of regional myocardial wall motion, which is a sensitive and specific marker of ischemia. In conjunction with an ECG-stress test the CKG helps to detect the evolving ischemic abnormalities of myocardial contraction. The CKG represents a marker of ischemia independent of the ECG and helps to improve the diagnostic accuracy of stress testing for detection of CAD. The stress CKG is especially advantageous in those cases in which the interpretation of the stress ECG is difficult or even not possible. Its simple and inexpensive technique makes it a useful adjunct to the stress ECG in the diagnosis of CAD.