Aims Radiofrequency (RF) ablation requires placement of several catheters at critical positions. The catheters are positioned with fluoroscopy, resulting in a significant radiation exposure. We have investigated to what degree an intracardiac navigation system reduces the fluoroscopy duration in different groups of routine RF ablations. Methods and results The fluoroscopy time was evaluated in 365 consecutive routine RF ablations, performed between 2002 and 2005. An intracardiac navigation system (LocaLisa, Medtronic) was used from 2003. The data were prospectively entered into a database and subsequently retrieved, and the procedures classified as being performed with fluoroscopy only or with the aid of the LocaLisa system. After introduction of the LocaLisa system, the median fluoroscopy time decreased from 24 to 10 min in the 141 atrioventricular nodal re-entry tachycardia (AVNRT) ablations and from 43 to 28 min in the 71 atrial flutter (AR) ablations (P < 0.005 for both). In the 145 Wotff-Parkinson-White (WPW) ablations, a decrease from 27 to 23 min was observed (P = 0.03). The decrease in AVNRT and AFI, but not in WPW was associated with the introduction of the LocaLisa system. Conclusion The use of the LocaLisa system during RF ablations significantly reduced the fluoroscopy time in AVNRT and AR ablations, by a median of 58% and 46%, respectively.