A 50 year old, recent cardiac transplant recipient developed systolic and diastolic murmurs but remained asymptomatic. The cause of the murmurs was not evident at transthoracic echocardiography. During routine left heart catheterisation a left anterior descending artery to right ventricular fistula was evident arising from the distal vessel and presumably acquired during routine endomyocardial biopsy. One year later, the patient remained asymptomatic but the calibre of the left anterior descending artery had increased and there appeared to be poor flow in to the proximal branches. The fistula was successfully treated by percutaneous deployment of two detachable embolisation coils in to the distal left anterior descending artery.