Carotid artery pseudoaneurysm is a rare disease, which is defined by the loss of integrity of the 3 layers of the arterial wall, and is caused by trauma, vasculitis, infection and unknown origins. Recently, we experienced a rare case of carotid artery pseudoaneurysm associated with NTM lymphadenitis. A 81-year old male was referred to ENT clinic for abscess drainage of left lateral neck mass. The patient had a history of NTM lymphadenitis and underwent anti-tuberculous medication with clarithromycin therapy for 2 months. Considering such past history, the condition was considered as aggravation of NTM lymphadenitis initially. However, physical examination showed a pulsatile mass and ultrasonographic doppler demonstrated arterial pulse. CT scan with angiogram showed a 6cm sized neck mass compatible with pseudoaneurysm of the carotid artery. The patient underwent interposition prosthetic grafting at the department of cardiovascular surgery. Surgical drainage without adequate evaluation may have led to potentially life-threatening condition. Therefore, carotid artery pseudoaneurysm is rare but should be considered in NTM lymphadenitis patients showing rapid enlargement of neck mass.