Objective: Takayasu arteritis (TA) is an idiopathic large-vessel vasculitis, predominantly impacting the aorta and its major branches. The management of TA includes pharmacotherapy or surgical intervention in the presence of complications. Design and method: A 14-year-old girl was admitted to our clinic for a thoracic aortic aneurysm. Initial symptoms include fever, loss of appetite, weight loss, muscle pain, followed by palpitations and abdominal pain, and loose stools. The test showed an increased hs-CRP level: 28.7 mg/L. Computed tomography angiography (CTA) chest with contrast showed two segments of thoracic aneurysms involving descending aorta, the aortic diameter of the superior and inferior segment aneurysms is #1.6-1.8 cm, #2x 2.1 cm, respectively, and the length is #2.5 cm, # 3.2 cm, respectively. According to JSC 2017, This patient was diagnosed with descending aorta aneurysms in Takayasu arteritis- type III (ACR 1994) The patient underwent corticosteroid therapy, starting with prednisolone at an initial dose of 20 mg/day. The dosage was reduced to 10 mg/day at month 3 and maintained at 5 mg/day from month 6 until the completion of the 18-month therapy. Additionally, low-dose aspirin (81 mg/day), ACE inhibitors, and beta-blockers were incorporated to enhance treatment efficacy. Results: After 3 months, hs-CRP levels returned to normal. After 12 months of combined treatment with corticosteroids and aspirin as described above, the patient's aortic diameter had returned to almost normal on CTA. The patient's symptoms improved after finishing treatment. Conclusions: Successful treatment of Takayasu arteritis in our case, highlights the significant role of pharmacotherapy. This cost-effective approach minimizes side effects, offering promising treatment options for Takayasu arteritis patients, especially in low-income countries like Vietnam