To test the hypothesis that local or diffuse wall motion abnormalities in the right ventricle in patients with arrhythmogenic right ventricular dysplasia (ARVD) may induce the ST-segment elevation in response to exercise, we examined exercise electrocardiograms in patients with ARVD. In 17 patients with ARVD, who demonstrated right ventricular wall motion abnormalities without organic coronary lesions, we conducted a treadmill exercise test. Significant exercise-induced ST-segment elevation (ESTE) was defined as a 0.1 mV or more ST-segment elevation at J point. ESTE was observed in 11 patients (65%). It manifested most frequently in right-sided precordial leads. Severe right ventricular asynergy was seen in all but one (91%) among 11 with ESTE, whereas it was seen only in two (33%) among six without ESTE (P<.05). The maximal magnitude of ESTE inversely correlated with right ventricular ejection fraction (r = -0.58, P<.05). ESTE was seen in two thirds of ARVD patients, helping us noninvasively diagnose ARVD. The fact that ventricular wall motion abnormalities could cause ESTE in the absence of organic coronary lesions suggested the critical role of mechanical factors in the genesis of ESTE.