The article presents a case of a 54-year-old female patient who, over the course of 2 years, suffered 5 cerebrovascular accidents (CVA) due to infectious arteritis of both internal carotid arteries (ICA) and basilar artery as a complication of sphenoiditis and otitis. According to neuroimaging data, the steno-occlusive process in the ICA developed gradually, starting with the intracranial ICA narrowing with the contrast enhancement by vessel wall, the development of its occlusion six months later, and the detection of the extracranial ICA occlusion with the formation of «flame sign» at its mouth a year later. Repeated examination of the cerebrospinal liquid at an early stage of the disease revealed cytosis up to 367/3 and protein 0.66 g/l. The correct diagnosis was established only after 3 years with a retrospective analysis of clinical, neuroimaging, and laboratory data. Therefore, targeted antibiotic therapy was not carried out, which led to the progression of ICA occlusion and repeated strokes. Infectious arteritis should be taken into account in the differential diagnosis of the causes of the ICA occlusive process.