Paradoxical embolism is one of the mechanisms of ischemic stroke in patients younger than 45 years of age, due to opening between the right and left chambers of the heart through a patent foramen ovale, an atrial or ventricular septal defect, pulmonary arteriovenous malformations (PAVMs), etc. The PAVMs are structurally abnormal vessels that provide direct capillary-free com-munication between the pulmonary and systemic circulations, and hence an anatomic “right-to-left” shunt. Most pulmonary malformations are congenital and associated with hereditary hemorrhagic telangiectasia (Rendu—Osler—Weber disease). This pub-lication highlights the issues of pathogenesis, clinical presentation, diagnosis and treatment of this pathology, and also describes a clinical case in which multiple PAVMs caused repeated ischemic strokes. © 2020, Media Sphera Publishing Group. All rights reserved.