This case aims to report a patient who presented with reduced vision in her left eye and was diagnosed with giant cell ar- teritis (GCA) associated with isolated cotton wool spots (CWS). An 82-year-old woman presented with reduced visual acuity of 20/200 in her left eye for a day. Fundus examination revealed only multiple peripapillary CWS in the left eye. She had an elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). A preliminary diagnosis of temporal arteritis, intravenous high-dose steroid therapy, was administered for 3 days. Then, the systemic symptoms resolved, and her ESR and CRP dropped. Temporal artery biopsy confirmed the diagnosis of GCA. The next 2 months, in the fundus examination, CWS resolved completely. The patient continued using systemic steroids and subcutaneous methotrexate with long-term gradual reduction. This extreme case should raise awareness for clinicians in the etiological investigation of CWS to identify sight-threatening GCA and promptly initiate appropriate treatment.