Aorta-pulmonary (A-P) artery fistula following a stab wound to the chest with superimposed infective endocarditis (IE) is a rare, often unrecognized presentation. Herein, we report a case of A-P fistula due to stab chest assessed by two- and three-dimensional (3D) imaging.A 30-year-old man presented with a history of being stabbed in the chest with a screwdriver. The chest wall laceration was sutured, an intercostal drain inserted for a haemopneumothorax, and he was subsequently discharged. He presented 3 weeks later with exertional dyspnoea, fever, rigours, and loss of weight. On examination, he had a wide pulse pressure and a harsh continuous murmur in the 2nd left intercostal space associated with a palpable thrill. Blood tests revealed raised infective markers and anaemia. All blood cultures were sterile. On echocardiography, the aortic and pulmonary valve was severely damaged, with suspicion of superimposed vegetations secondary to IE. There was severe aortic and pulmonary valve regurgitation. A fistulous connection was noted between the aorta and main pulmonary artery, just below the commissure adjoining the right and left coronary sinus of the aortic valve. On 3D imaging, the defect was quantified. The patient was subsequently referred for aortic and pulmonary valve replacement and closure of the A-P fistula. The presence of multiple vegetations was confirmed intraoperatively. He also received a 6-week course of intravenous antibiotics.We have described a rare case of an A-P fistula due to a stab wound to the chest complicated by IE. In a patient with stab wound to the chest, a high index of suspicion of cardiac involvement must be maintained, and a careful search for intracardiac shunts must be made on echocardiography, prior to discharge. Furthermore, in addition to two-dimensional imaging, 3D imaging proved useful in providing a comprehensive assessment of the morphology of the lesion prior to surgery.