Polymorphic ventricular tachycardia (PVT) is a fatal arrhythmia that can occur during the treadmill test. This report documents an instance of PVT by the R-on-T phenomenon during an exercise stress test in a 61-year-old male with stable angina pectoris. The subject performed the treadmill test for 581 seconds, and stopped after reaching 115% of the target heart rate. Ischemic ST changes were observed in leads II, III, aVF, and V3-V6 from stage 3. Premature ventricular complexes were noted during the recovery period, with an occurrence of pulseless PVT, reflective of the R-on-T phenomenon. Spontaneous circulation was resumed after unsynchronized cardioversion at 200 J and 2 minutes of cardiopulmonary resuscitation. Emergency coronary angiography revealed 95% stenosis of the proximal right coronary artery, which was fully dilated after percutaneous coronary intervention with a drug-eluting stent. The patient was discharged without any neurologic sequelae.