Posterior ischaemic stroke is relatively uncommon, and its occurrence should alert clinicians to possible uncommon underlying disease. We report a patient with occipital brain infarction. The combination of age, gender, general malaise and elevated erythrocyte sedimentation rate led to the clinical suspicion of giant cell arteritis. Vertebral artery vasculitis was confirmed by 18-FD G positron emission tomography, combined with CT angiography, and immediate immunosuppressive therapy was started. Symptoms of stroke should, in a particular clinical context, raise suspicion of giant cell arteritis.