Aorto–left ventricular tunnel is a rare congenital cardiac anomaly characterised by an extracardiac channel connecting the ascending aorta directly to the left ventricle. Surgical repair in neonates poses significant challenges due to the diminutive size and close proximity of critical structures such as the aortic valve and coronary ostia. We report the case of a neonate with an aorto–left ventricular tunnel, mild left ventricular dysfunction, and mild aortic insufficiency who underwent successful surgical repair on the sixth day of life. Following cardiopulmonary bypass initiation and cardioplegic arrest, the ascending aorta was transected for direct visualisation. A 5-mm 0° rigid endoscope was employed intraoperatively, providing high-resolution magnification of the aortic valve, right coronary artery, and tunnel anatomy. The tunnel was closed using an autologous pericardial patch, ensuring preservation of the coronary ostium and aortic valve integrity. Postoperative echocardiography demonstrated good left ventricular function, trivial aortic insufficiency, and no residual shunt. The use of rigid endoscopy significantly enhanced the safety and precision of the repair by allowing accurate anatomical delineation and facilitating patch placement. This case highlights the importance of detailed visualisation in neonatal aorto–left ventricular tunnel repair and underscores the utility of rigid endoscopic technology in complex congenital heart surgery. Endoscopic assistance not only aids intraoperative decision-making but also serves as a valuable tool for surgical education and postoperative review.