A 9-month-old boy with cardiovocal syndrome--paralysis of the left recurrent laryngeal nerve, and congenital heart disease--a double outlet of the right ventricle and pulmonary arterial hypertension is described. He had a hoarse cry due to left recurrent laryngeal nerve paralysis, which was diagnosed by indirect laryngoscopy. Paralysis was caused by traction of the enlarged great arteries on the left recurrent laryngeal nerve. After heart surgery the infant's voice returned to normal. It is important to recognize this rare syndrome at an early stage, as it may cause difficulties in postoperative respiratory management.