Introduction: Fasciculoventricular(FV) pathways are the rarest form of preexcitation, and not directly responsible for arrhythmias. We analyzed the electrocardiographic findings of the patients with FV pathways confirmed by electrophysiologic studies Methods and Results: From January 1993 to June 2003, total five of 168 patients underwent electrophysiologic studies for evaluation of preexcitation on surface ECG were diagnosed as FV pathways. Standard 12-lead ECGs were analyzed in these patients. Two of five patients had no inducible supraventricular tachyarrhythmias, and three patients had paroxysmal atrial fibrillation, atrial flutter, and atrioventricular nodal reentrant tachycardia, respectively. The insertion sites of FV pathways were anteroseptal area, and overall features of delta waves and QRS morphologies were similar with the ECGs of Wolff-Parkinson-White (WPW) syndrome with anteroseptal accessory pathways. However, PR intervals were not significantly shortened (mean 짹 SD: 122짹11.0 ms, range: 110-140 ms). The vectors of delta waves in V1 lead were flat (four of five patients) or negative (one of five) in contrast with the cases of WPW syndrome with anteroseptal accessory pathways in which the vectors of initial delta waves were positive in V1. Three of five patients had notching in the descending limb of S waves in V1 and one patient had q wave in V1. Both of these findings were not observed in WPW syndrome with anteroseptal accessory pathways. Conclusion: Electrocardiographic findings of FV pathways are similar with those of WPW syndrome with anteroseptal accessory pathways. However, differential diagnosis of FV pathways is possible by using differences in PR interval and morphology of delta waves and QRS complexes in V1 lead in standard 12-lead ECG.