Unilateral absence of a pulmonary artery (UAPA) is a rare congenital condition and coexists with cardiovascular abnormalities such as cyanotic heart disease or cardiac septal defects; however, it can also occur in isolation. Patients with isolated UAPA can progress without symptoms into late adulthood but usually present with dyspnea, chest pain, hemoptysis, or recurrent infections. There are no reported guidelines on the treatment of UAPA. The plan of treatment is based on the presenting symptoms, pulmonary artery (PA) anatomy, aortopulmonary collaterals, associated cardiovascular anomalies, and pulmonary hypertension. The objectives of unifocalization are to consolidate the multiple sources of pulmonary blood flow, to unite the multiple pulmonary collateral arteries, and to remodel a new central artery that can be created with a prosthetic conduit. Usually, a modified Blalock-Taussig shunt, a surgical systemic pulmonary shunt, is used to perfuse the pulmonary arteries. The perioperative course and management of a case of UAPA for unifocalization have rarely been reported in the literature. Here, we discuss the perioperative management of a case of unilateral absence of the right PA (RPA) for unifocalization.