Periprocedural neurological complications (PNCs) after carotid stenting were retrospectively analyzed to determine the risk factors with the use of various protective devices. Forty-three lesions in 40 patients were treated by carotid stenting with distal balloon protection for nearly all postdilation procedures and some predilation procedures. The following variables were statistically analyzed for association with PNCs: diameter of the angioplasty balloon used for predilation, use of a distal protection balloon during predilation, use of a protection balloon during postdilation, lesion-bifurcation distance, length of the lesion, age, clinical presentation of the lesion (symptomatic or asymptomatic), and hypercholesterolemia. PNCs occurred in five patients, four with minor deficits and one with major deficits. Univariate analysis showed large diameter of the predilation angioplasty balloon (p = 0.0026), use of a protection balloon during predilation (p = 0.0075), lesion length (p = 0.0003), and lesion-bifurcation distance (p = 0.0006) were significantly associated with PNCs. Multivariate analysis of these four variables showed that use of a large angioplasty balloon for predilation was the only independent predictor (p = 0.004, odds ratio 34.00) for the occurrence of PNCs. Use of a large angioplasty balloon for predilation carries the risk of periprocedural embolic complications. Therefore, even when a protection device is used, predilation should be performed with a small balloon.