The size of present rotational atherectomy devices is limited in part by a tendency to produce vessel torsion. The authors designed and investigated a large-bore rotational atherectomy device for peripheral atherectomy in a single pass without significant torsion. A plaque was retrieved from 36 of 40 cadaveric iliac arteries. The mean plaque size was 8.4 x 3.9 mm, and the average number retrieved per artery was two. Thirty of 34 severely calcified arteries were treated successfully. Effluent study revealed no distal embolization; however, six perforations and four dissections occurred. Preliminary results suggest that a cutting surface with a relatively large diameter can be designed to be effective without producing vessel torsion. Changes in future designs will include added flexibility and expandable cutting surfaces to enhance safety and minimize entry diameter.