We report the case of a 3,5 month-old infant presented at cardiology consultation of our institution for investigation of a heart murmur associated with failure to thrive and respiratory distress. Echocardiogram showed dilatation of left heart cavities, patent foramen ovale, small muscular ventricular septal defect and pulmonary hypertension. Angio-CT was performed on a 64-slice CT to better characterize the congenital heart disease. Aortopulmonary window was diagnosed and surgically corrected. Patient evolution was good with discharge 10 days after surgery. The authors review the literature and stress the importance of angio-CT in pre-operative evaluation.