Introduction: Acute upper extremity ischemia is an uncommon vascular emergency due to a relatively rich collateral network and low workload of the upper limb. Its consequences depend on the site and etiology of the arterial occlusion. Case presentation: Aiming to emphasize the emerging role of Doppler ultrasound in the diagnosis of acute upper limb ischemia, we report the case of a 70-year-old female, with severe left arm resting pain and digital cyanosis. Due to the patient’s age and the presence of cardiovascular risk factors, cardioembolic or thrombotic arterial occlusion would have been the most likely diagnosis in this case, but the color Doppler ultrasound revealed severe left axillary arterial stenosis with hypoechoic wall swelling, being highly suggestive for arteritis. Temporal artery biopsy was performed, which confirmed giant cell arteritis. An excellent clinical response was obtained after initiation of treatment with corticosteroids. Conclusion: In acute upper limb ischemia, color duplex ultrasound provides quick information about the etiology and localization of arterial lesions, offering characteristic findings in case of large-vessel giant cell arteritis. The routine use of this method in patients with clinical signs of upper limb ischemia and the fact that atypical localizations of giant cell arteritis may be present lead to fewer delayed or missed diagnoses.