AbstractAnatomically Corrected Malposition of the Great Arteries (ACMGA) is an exceedingly rare congenital heart anomaly in which the great arteries emerge in parallel, with an abnormal spatial relationship to the ventricles, despite originating from anatomically corrected chambers. This case report presents a 36-year-old female who was referred for evaluation of dyspnea on exertion and was initially diagnosed with severe pulmonary stenosis (PS). Echocardiography and cardiac magnetic resonance imaging (CMR) confirmed the diagnosis of ACMGA, in which the atrioventricular and ventriculoarterial relationships were concordant, but the great arteries were malposed, with a leftward malposition of the aorta. Transesophageal echocardiography revealed an isolated subaortic conus, as well as severe valvular and subvalvular pulmonary stenosis. The patient was subsequently scheduled for surgical correction. This report highlights the importance of accurate diagnosis and differentiation of ACMGA from other congenital heart defects, as misdiagnosis can lead to inappropriate treatment strategies. Advanced imaging modalities such as CMR play a crucial role in diagnosing this rare condition, especially in adult patients with poor echocardiographic windows.Keywords : anatomically corrected malposition of the great arteries (ACMGA), left malposition of the aorta, isolated subaortic conus, cardiac magnetic resonance imaging (CMR)