Background : Absence of right pulmonary artery (RPA) is a rare congenital abnormality with variable presentation. The diagnosis is often missed in infants Objective : The aim of this study was to describe infantile presentation of isolated absence of RPA along with a brief review of the literature. Methods : The details of five patients diagnosed with isolated absence of RPA from April 2007 to October 2009 were reviewed retrospectively Results : Five patients were identified with this anomaly. The median age of presentation was 86 days (range, 40-120 days) and the median weight was 3.65 kg (range, 3.1-5.5 kg). All patients presented with breathing difficulty and had severe pulmonary hypertension (PHT) along with absent RPA on echocardiography. A multidetector computed tomographic scan was performed to confirm the diagnosis in four cases. Three patients had major aortopulmonary collateral and the hilar RPA was not well developed in all. A correct diagnosis was made before referral in one patient only. Differential vascularity in chest X-ray, a useful clue, was seen in four of five cases. Surgical correction was not considered in view of the small hilar pulmonary artery. The patients were all managed medically with diuretics and Sildenafil. Conclusion : Isolated absence of RPA is a rare congenital abnormality with varied presentation. Infantile presentation is marked with congestive cardiac failure and PHT. Specific diagnostic clue includes differential vascularity on the chest X-ray.