We describe our experience with a technique for PTCA of total coronary occlusions using the ultra low profile balloon on wire Probe. An intracoronary Probing Catheter was used to facilitate crossing the stenosis with a guide wire. This was followed by exchanging the guide wire for the Probe into the obstruction for balloon dilatation. This technique was used in 22 consecutive patients undergoing PTCA for chronic total occlusion. The total obstruction could be crossed by guide wire (0.014 flex or 0.016 standard) passed through Probing Catheter in 19 patients (86%). The obstruction could be successfully dilated by the Probe, delivered through the probing catheter, in 17 of these patients. Of the remaining 2 patients, one could be dilated by sequential dilatation using over the wire low profile balloon system and the other one by dilatation with the Probe, respectively. The Probing Catheter technique offers a new method to apply balloon on wire technology to the dilatation of chronic total coronary occlusions with very promising results.