Truncus arteriosus communis is a rare CHD, accounting for only 1% of all congenital cardiac abnormalities. It has been associated with other malformations of the heart, mainly truncal valve (bicuspid/quadricuspid) and aortic arch abnormalities such as right, interrupted, and hypoplastic aortic arch. Cor tratriatrum sinistrum is another rare CHD, and it has been associated with other cardiac defects such as anomalous pulmonary venous drainage, ventricular septal defect, coarctation of the aorta, and tetralogy of Fallot. The combination of truncus arteriosus communis and cor tratriatrum sinistrum has not been reported so far. This case study describes the diagnosis of a unique case, including these two very rare cardiac defects and the successful surgical treatment thereafter.