Rotational atherectomy (Rotablation) represents one of the alternative devices to treat complex coronary artery stenoses. Rather than increasing luminal diameter by arterial stretching and plaque fracture as with balloon angioplasty, rotablation debulks atherosclerotic plaque with an abrasive diamond coated burr. The basic physical principle is differential cutting. It allows the advancing burr to selectively cut inelastic material while elastic tissue deflects away from the burr. 95% of the particles generated by the Rotablator are less than 5 microns. They are removed by the body's reticuloendothelial system. There are different strategies to perform a rotablation, regarding the number of burrs used and the final burr-to-artery ratio. An adjunctive PTCA is recommended without proof by randomized studies so far. The best indication for the Rotablator is the undilatable lesion. Lesion modification (debulking) as a method of improving vessel compliance seems to be also usefull in diffusely diseased and calcified vessels, as well as in aorto-ostial and angulated stenoses. The instent restenoses is a new indication. Randomized studies will have to proof if there is an advantage for rotablation compared to PTCA. Restenosis rates appear comparable to balloon angioplasty.