Objective: To compare the therapeutic efficiency and safety of radiofrequency catheter ablation (RFCA) for paroxysmal ventricular tachycardia (PSVT) guided by three-dimensional navigation with X-ray. Methods: One hundred and seventy-six patients with PSVT hospitalized in Department of Cardiology, Zhejiang Provincial People's Hospital between January 2013 and December 2014 were enrolled in this study. RFCA was performed on 95 patients (Group A) guided by the three dimensional electric-field navigation system (NavX) and the procedures were done with the spatial localization method, unless X-ray was needed in some cases.Eighty-one patients (Group B) underwent RFCA guided by X-ray only.The success rate, complications, recurrence rate, operation time, and X-ray exposure were compared between the two groups. Results: The immediate success rate of operation was 100% in the 176 PSVT patients without complications.There were recurrences in 2 cases of Group A, while in 1 case of Group B. The average operation time in Group A was (97±20) min, while (91±26) min in Group B. The median X-ray fluoroscopy time was 3.0 min and radiation dose was 18.5 μGym2 in Group A, which were significantly reduced compared with those in Group B (34.5 min, 167.3 μGym2) (P<0.05). There was no significant difference in immediate procedure success rate, complications, recurrence, and operative time between this two groups (P>0.05). Conclusions: The RFCA for PSVT guided by three-dimensional navigation is safe and feasible in the experienced electrophysiological center.Most patients suffer less or no X-ray radiation.