Aberrant bronchial arteries are rarely seen and may originate from various vascular structures. Hemoptysis is the most common clinical presentation of cases with anomalous bronchial artery. We report a case of a 1-month-old infant presented with respiratory distress and left lung emphysema. Radiologic investigations and bronchoscopy revealed that the cause is an aberrant left bronchial artery compressing the left main bronchus. Surgical division of the aberrant vessel was performed with gradual improvement of the emphysema and respiratory distress. Unilateral emphysema due to vascular compression was previously reported. However, to the best of our knowledge, this is the first reported case of aberrant bronchial artery presenting with external compression of a main bronchus and unilateral emphysema. Also, this is the youngest reported case with an aberrant bronchial artery.