Background: There are limited reports on the treatment of complex calcified lesions using rotational atherectomy (RA) in octogenarians, particularly in high-risk patients. Objective: To evaluate procedural and clinical outcomes of RA in octogenarians. Methods: Consecutive RA patients from2010 to 2018were selected from our catheterization laboratory database, stratified into two groups (≧ or < 80 years old), and analyzed. Results: A total of 411 patients (269 males and 142 females) with a mean age of 73.8 ± 11.3 years were enrolled, of whom 153 were ≧ 80 years old and 258 were < 80 years old. Most of the patients displayed high-risk features. The baseline Syntax scores were high in both groups, and most lesions were heavily calcified (96.1% vs. 97.3%, p = 0.969, respectively). The use of hemodynamic support intra-aortic balloon pump was more frequent in the octogenarians (21.6% vs. 11.6%, p = 0.007), but the RA completion rate was similarly high (95.9% vs. 99.1%, p = 0.842). There was no difference in acute complications. The total/cardiovascular (CV) death rate within one year was higher in the octogenarians, along with higher major adverse cardiovascular event (MACE)/CV MACE rates in the first month. Cox regression analysis showed that age ≧ 80 years, acute coronary syndrome, ischemic cardiomyopathy/shock, multi-vessel disease and serum creatinine were all predictors of MACE, and that these factors plus peripheral artery disease were predictors of all-cause mortality in these patients. Conclusions: RA is feasible with a very high success rate in high-risk octogenarians with complex anatomies, and with equal safety and no increase in complications. The higher rates of all-cause death and MACE were attributed to an older age and other traditional risk factors.