Unilateral phrenic nerve paralysis after cardiothoracic surgery is not uncommon. When symptomatic, it can require surgical treatment. Plication of the diaphragm through a thoracotomy is known to provide excellent long-term results. Plication is now being performed via video-assisted thoracoscopic surgery (VATS). We report the cases of two patients with postoperative left phrenic nerve paralysis who underwent plication of the diaphragm using VATS and achieved total relief of all symptoms.