Atrial septal defect (ASD) is often diagnosed and repaired during childhood. Nevertheless, it is the most common congenital cardiac defect seen in adults. ASD is characterized by a left-to-right intracardiac shunt and pulmonary hypertension. Pulmonary hypertension increases perioperative risks of morbidity and mortality. We report the anaesthetic management of a 68-year-old woman with an unrepaired ASD, who underwent a total hip arthroplasty under continuous spinal anaesthesia.