Background and purpose Perforator stroke is one of the most common complications of elective intracranial angioplasty and/or stenting, particularly in the basilar artery. Factors associated with the risk of post-procedural perforator stroke remain unexplored. We investigated factors affecting the risk of perforator stroke after basilar artery angioplasty and/or stenting. Materials and methods Consecutive patients undergoing basilar artery angioplasty and/or stenting due to symptomatic atherosclerotic stenosis were retrospectively included in this single-center study. Analyzed variables including demographic data, risk factors of atherosclerosis, symptoms, characteristics of imaging, and procedure factors were extracted from electronic health records or imaging data. The main outcome was perforator stroke associated with the procedure. Multivariate analysis that correlated factors with the occurrence of perforator stroke in these patients was performed. Results A total of 255 patients were included in the study. Perforator stroke associated with angioplasty and/or stenting was identified in 13 patients (5.1%). Variables with significant correlation with post-procedural perforator stroke included diabetes (OR 6.496; 95% CI 1.741 to 24.241; p=0.005), time from last symptom to procedure <18 days (OR 5.669; 95% CI 1.174 to 27.371; p=0.031), and pre-procedure stenosis percentage <88.4% (OR 5.882; 95% CI 1.465 to 23.608; p=0.012). Conclusions Diabetes, time from last symptom to procedure, and pre-procedure stenosis percentage may be factors affecting the risk of perforator stroke associated with basilar artery angioplasty and/or stenting. These factors should be considered in planning of potential basilar artery angioplasty and/or stenting and prospectively evaluated in future multicenter trials.