Background: Left-sided partial anomalous pulmonary venous connection (PAPVC) is a rare congenital abnormal cardiac defect. An intact atrial septum is more uncommon. As we know, a connection of the left pulmonary vein (LPV) to the coronary sinus (CS) with an intact atrial septum has not been previously reported. Case report: We report an 18-year-old woman with this rare anomaly. She showed no obvious clinical symptoms. An echocardiogram revealed the primary diagnosis, and this diagnosis was confirmed during the operation. This patient underwent a successful surgical repair. Artificial atrial septal defect (ASD) and coronary sinus orifice were inserted into the left atrium by patch. The patient recovered smoothly without complications after the operation. Conclusion: Given the high risk of developing congestive heart failure, we advocate for intervention at the preschool age. Surgical techniques depend on the number and location of abnormal veins or veins.