Unilateral pulmonary artery agenesis (UPAA) is the complete absence of either the right or left pulmonary artery. It is a rare congenital malformation, usually associated with other cardiac defects
however, in some cases, it may occur as an isolated lesion, typically affecting the right side. Patients with isolated right pulmonary artery agenesis are often diagnosed incidentally on chest radiographs in adulthood. Rare cases are associated with multiple systemic collaterals that supply the affected lung. We report the case of a 69-year-old man with the absence of a right pulmonary artery, arterial supply to the right lung from the celiac trunk, and communication of the collaterals with a marginal branch arising from the right coronary artery. UPAA is a rare congenital anomaly that may present with nonspecific symptoms, such as dyspnea and recurrent chest infections. Clinicians should consider UPAA in the differential diagnosis of respiratory symptoms, particularly in adult patients with unexplained symptoms.