: Giant cell arteritis (GCA) is a type of large and middle arteries vasculitis that occurs in patients aged over 50 years. The typical symptoms include pain and tenderness in the temporal region, sudden vision impairment or loss and jaw claudication. If left untreated the disease may lead to permanent blindness. The diagnosis is based on the ACR criteria and the treatment of choice are glicocorticosteroids. The ultrasonography with color Doppler is characterized by high sensitivity and specificity which makes it a valuable diagnostic tool, especially in questionable cases. A case report: 86-year-old woman, with a history of sudden left eye vision loss that occurred one month ago, reported to the hospital due to right eye vision impairment progression. The symptoms and characteristic of patient's complaints suggested GCA, however patient didn't meet the diagnostic criteria. The ultrasonography examination was used, which revealed features typical for GCA ("halo" sign and non-compressible arteries - compression sign), which contributed to the decision of the immediate treatment initiation with corticosteroids which stopped the progression of the disease and led to the slight right eye vision improvement.

Conclusions: The ultrasonography examination is a useful and valuable diagnostic tool for patients with suspected GCA and its use is especially significant in the questionable cases diagnosis.