Balloon angioplasty is an accepted treatment for arterial obstruction; however, a substantial percentage of initially successfully treated lesions recur in the first 4 to 6 months. There is increasing interest in local treatment of lesions undergoing angioplasty to prevent restenosis, and an infusion catheter has been developed for this purpose. This study compared infusion balloon angioplasty by means of saline solution with conventional balloon angioplasty in atherosclerotic iliac arteries of 18 cholesterol-fed New Zealand white rabbits. Values for minimum stenosis diameter assessed angiographically immediately after maximum infusion balloon angioplasty (2.1 +/- 0.6 mm) and after conventional balloon angioplasty (2.3 +/- 0.3 mm, p = NS) were similar. In follow-up studies up to 5 weeks after angioplasty, the angiographic minimum stenosis diameter remained similar in the two treatment groups, but the histologically assessed intimal area was greater after infusion angioplasty (1.54 +/- 0.92 mm vs 1.02 +/- 0.75 mm in conventionally treated arteries, p = 0.0001). Infusion balloon angioplasty merits further evaluation as a treatment strategy for the simultaneous dilatation of atherosclerotic lesions with delivery of therapeutic agents to minimize restenosis.