Introduction: Ventricular entrainment is useful to distinguish atrioventricular nodal reentrant tachycardia (AVNRT) from atrioventricular reentrant tachycardia (AVRT) by subtracting the ventriculoatrial (VA) interval during tachycardia from the interval between the last pacing stimulus and the last entrained atrial electrogram (SA). We tested the hypothesis whether induced right ventricular (RV) extrastimuli (V 2 ) resetting tachycardia would be equivalent or superior to ventricular entrainment to distinguish AVNRT from AVRT. Methods: Patients with either AVNRT or AVRT who underwent electrophysiological study in three institutions were investigated. The entire tachycardia cycle length (TCL) was scanned with V 2 delivered from the RV apex. SA-VA differences were calculated with V 2 clearly resetting the tachycardia even when it was delivered prior to His refractory period. The prematurity of V 2 was assessed the V 2 coupling interval (CI) divided by the TCL. Results: A total of 189 patients (age 37.0 ± 22.3 years; 104 male) were included. There were 92 AVNRT (including 5 atypical forms) and 97 AVRT including 7 AVRT with decremental accessory pathway (AP). SA-VA difference was more than 70 ms in all AVNRT and was less than 70 ms in all AVRT with right and septal AP except those with decremental AP. There was significant negative correlation between SA-VA and CI/TCL ratio in both AVNRT and AVRT without decremental AP. A SA-VA difference <110 ms with CI/TCL less than 65% distinguished AVRT using left AP from AVNRT with sensitivity, specificity, positive and negative predictive values of 100%, 88%, 68%, and 100%, respectively. Ventricular entrainment resulted in tachycardia termination or AV dissociation in 31% compared with 16% using the V 2 technique (P = 0.0024). Conclusions: A SA-VA of 70 ms using the V 2 technique proved excellent for differentiation of AVNRT from AVRT using septal and right AP. There was overlap between AVNRT and AVRT with decremental AP or with left AP, but use of the V 2 technique with short CI (<65% TCL) differentiated AVNRT from AVRT using left AP. This technique less frequently resulted in tachycardia termination than ventricular entrainment.