© Copyright 2016 by Türkiye Klinikleri.Objective: Catheter ablation therapy with radiofrequency ablation has been used to treat heart rhythm disorders such as supraventricular tachycardia including accessory pathway or atrioventricular nodal reentry, atrial flutter and atrial fibrillation and ventricular tachycardia. The body weight may be an important factor for injury of radiation. Therefore, this article describes the correlation between the fluoroscopic time and body weight during cardiac radiofrequency (RF) catheter ablation procedures. Material and Methods: Eighty-six consecutive patients [70 atrioventricular nodal re-entrant tachycardia, 10 atrioventricular re-entrant tachycardia (6 Wolff-Parkinson-White syndrome), two atrial flutter, two atrial fibrillation, and two right ventricular outflow tract tachycardia] with symptomatic drug-resistant tachycardia underwent an invasive electrophysiological study and RF ablation. The fluoroscopy time and radiofrequency ablation time were measured during electrophysiological study. Results: Body-mass index was significantly increased in woman patient than man patient. But there were no significance differences the age, height, weight, waist/hip ratio, systolic blood pressure, diastolic blood pressure, heart rate, fluoroscopic time and radio frequency ablation time between man and woman. There was a correlation between fluoroscopic time and body weight (p=0.02, r=0.29) and body mass index. Conclusion: The study showed that there was a positive correlation between the fluoroscopic time and body weight in patients with radiofrequency ablation for tachycardia. This conclusion could be used to help prevent early and/or late radiation injuries, especially owerweight patients, during RF catheter ablation procedures.