Objective: This study aimed to evaluate the incidence and related factors of acute asymptomatic brain infarcts (aABI) following percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) via the right radial approach. Patients and methods: Two hundred ten consecutive patients with AMI were enrolled. Multiple factors were compared between patients with (n = 37) and without (n = 138) aABI in 175 patients who underwent PCI. Results: Of 175 patients with AMI, 37 (21.14%) developed aABI as determined by diffusion-weighted magnetic resonance imaging (MRI). Incidence of hypertension, proportion of primary PCI (p-PCI), Killip > 1 on admission, duration of procedure, and the frequency of device insertion into the coronary artery significantly differed between the aABI and non-aABI groups. These significant factors were reevaluated using logistic regression. Proportion of p-PCI, duration of the procedure, and the frequency of device insertion into the coronary artery were indicated as independent factors related to the incidence of aABI and others did not. Conclusion: Cranial MRI imaging following PCI revealed that 21.14% of the patients with AMI had aABI. The independent factors related to aABI following PCI were p-PCI, duration of the procedure, and the frequency of device insertion into the coronary artery. Copyright (C) 2014, Taiwan Society of Geriatric Emergency & Critical Care Medicine. Published by Elsevier Taiwan LLC. All rights reserved.