We report an unusual case of a 58-year-old female with idiopathic dissection of the left subclavian artery to the brachial artery which provoked vessel narrowing in the acute phase and was spontaneously repaired without surgical procedures in the chronic phase. We describe the serial imaging findings of the angiography and ultrasonography which demonstrate restoration of the dissection. In carefully selected patients, conservative management could be an alternative treatment to surgery or stenting with an excellent outcome.