Takayasu's arteritis is a chronic inflammatory disease that primarily involves the aorta and its main branches. Varying degrees of narrowing, occlusion, or dilatation develop in the involved vessel segments. However, dissection of the aorta is quite rare in this disease, and it may develop particularly after angioplasty. We report a very rare case of Takayasu's arteritis with dissection of the abdominal aorta just distal to the origin of the inferior mesenteric artery in a 9-year-old girl. She was treated conservatively with close follow-up. At the end of 1 year's follow-up, the dissection of the aorta did not show progression, and new lesions were not identified. To our knowledge, this patient is the youngest child presented with arterial dissection as the initial manifestation of the disease.