A thrombosed giant aneurysm of the V1 and V2 segments of the vertebral artery (VA) is rare. Therefore, there is controversy regarding its optimal treatment. A case of a symptomatic giant VA aneurysm located in the V1 to V2 segments on the left treated successfully by endovascular trapping of the VA is reported. A 68-year-old woman presented with swelling in the left anterior neck. Computed tomography angiography (CTA) showed a giant aneurysm measuring 47 × 58 × 47 mm3 in the left neck. Ten days after her first visit, she presented with sudden onset of left anterior neck pain. Repeated CTA showed a partial thrombus in the aneurysm. Angiography showed two thrombosed giant aneurysms located in the V1 to V2 segments of the left VA. After endovascular trapping for the aneurysms, the anterior neck pain resolved and the aneurysm gradually shrank. This case demonstrates that endovascular surgery is better than open surgery because it is less invasive. When performing endovascular treatment, trapping will be an alternative strategy for a symptomatic giant thrombotic aneurysm of the V1 and V2 segments of the VA if the patient can tolerate ischemia.