A 73-year-old man with idiopathic premature ventricular contractions (PVCs) underwent electrophysiological testing. Left ventricular activation mapping revealed a focal mechanism of the PVCs with the earliest activation on the anterior papillary muscle (APM). Irrigated radiofrequency (RF) current delivered at that site induced a cluster of non-sustained ventricular tachycardia episodes with the same QRS morphology as the PVCs, followed by ventricular fibrillation (VF). The APM might have served as an abnormal automatic trigger and driver for the VF occurrence. Ventricular fibrillation may occur as a complication during RF catheter ablation of papillary muscle ventricular arrhythmias even if the clinical arrhythmia is limited to PVCs.