In this case report, we describe a male patient, aged 65 years, with previous arterial hypertension and atrial fibrillation, with irregular use of losartan, presenting with sudden onset of dizziness, dysarthria, and bilateral ataxia, 5.5 h before the admission to the neurological emergency department. The cranial magnetic resonance imaging revealed hyperintensities on T2/FLAIR sequences, and diffusion restriction in the territory irrigated by both superior cerebellar arteries, alongside with left pontine, compatible with infarct. The CT angiography of the cervical and cerebral arteries revealed a thromboembolic occlusion of the top of the basilar artery. Furthermore, atrial fibrillation was confirmed based on the results of the electrocardiogram. During hospitalization, the patient was treated with metoprolol and dabigatran. Upon discharge, the patient demonstrated a partial improvement in symptoms under medication and was scheduled to return to the outpatient clinic after 30 days. Our case highlights the importance of considering ischemic stroke in the territory of the cerebellar superior artery bilaterally, due to a top of basilar thrombus, in patients presenting with global cerebellar ataxia, with no consciousness or visual alteration. Clinical Trial Number Not applicable.