Objective: Partial anomalous pulmonary connection is a rare adult congenital heart disease caused by abnormal return of one or more, but not all, of the pulmonary veins to the right atfium or indirectly through venous connections from the anomalous pulmonary vein.Presentations vary from incidental findings to severe heart failure.Diagnosis can be easily missed.Method: We report a case of a 51 year old male with history of coronary artery bypass surgery at the age of 39 when he presented with progressive exertional angina.During the past decade, despite medical optimization for coronary disease, he had persistent exertional symptoms of chest discomfort and dyspnea.These symptoms were interpreted as anginal in light of the patients known coronary disease and prior revascularization.His multiple coronary angiograms revealed patent grafts and stent.His physical examination revealed jugular venous distension, loud P2 with wide, but not fixed, splitting of S2, holosystolic murmur at lower left sternal border and trace pedal edema.Electrocardiography showed incomplete right bundle branch block pattern.Chest x ray showed enlarged right atrium with prominent pulmonary vascular markings.Transthoracic echocardiogram showed enlarged right atrium and right ventricle, severe pulmonary hypertension with normal left ventricular function.Transesophageal echocardiogram confirmed these findings and suggested the possibility of anomalous pulmonary venous drainage.Computed tomography angiograms of the chest revealed that anomalous drainage of right superior pulmonary vein into right atrium without evidence of pulmonary embolism or parenchymal lung disease to explain pulmonary hypertension.Results: The patient underwent surgical repair with redirection of the pulmonary connection to the left atrium by creation of atrial septal defect and interatrial baffle with bovine pericardium.On follow up, patients symptoms have improved with normalization of pulmonary artery pressure and the sizes of right chambers.Conclusion: The diagnosis may be particularly elusive when the patient also has a more common diagnosis, such as the coronary disease.Unexplained pulmonary hypertension and enlarged right sided chambers shall alert physicians to consider additional differential diagnoses including congenital heart disease despite the patients adult age.As evidenced in this patient, successful surgical repair can lead to gratifying results and improved prognosis.