Here, we present a case of partial anomalous pulmonary venous return with the superior type of sinus venosus atrial septal defect. This case also had unusually persistent left-sided superior vena cava, which could not be diagnosed well in preoperative transthoracic echocardiography and required contrast-enhanced cardiac computed tomography scanning for proper diagnosing, operative planning, and avoidance of intraoperative problems. Postoperative, cardiac computed tomography scanning was also done to confirm adequate management.