Background: Carotid angioplasty and stenting (CAS) is an accepted treatment to prevent stroke in patients with carotid artery stenosis. The purpose of this study is to identify risk factors for major complications after CAS. Materials and Methods: This is a prospective study that was conducted at Shiraz University of Medical Sciences in southern Iran from March 2011 to June 2014. Consecutive patients undergoing CAS were enrolled. Both standard- and high-risk patients for endarterectomy were enrolled. Demographic data, atherosclerotic risk factors, site of stenosis, degree of stenosis, and data regarding technical factors were recorded. Thirty-day stroke, myocardial infarction, and/or death were considered as the composite primary outcomes of the study. Results: A total of 251 patients were recruited (mean age: 71.1 ± 9.6 years; male: 65.3%). Of these, 178 (70.9%) were symptomatic, 73 (29.1%) were diabetic, 129 (51.4%) were hyperlipidemic, 165 (65.7%) were hypertensive, and 62 (24.7%) patients were smokers. CAS was performed for left internal carotid artery (ICA) in 113 (45.4%) patients. Fourteen (5.6%) patients had sequential bilateral stenting. Mean stenosis of operated ICA was 80.2 ± 13.8%. An embolic protection device was used in 203 (96.2%) patients. Pre- and postdilation were performed in 39 (18.5%) and 182 (86.3%) patients, respectively. Composite outcomes were observed in 3.6% of patients (3.2% stroke, 0% myocardial infarction, and 1.2% death). Left-sided lesions and the presence of diabetes mellitus were significantly associated with poor short-term outcome (p = 0.025 and p = 0.020, respectively). Conclusion: There was a higher risk of short-term major complications in diabetic patients and for left carotid artery intervention.