Abernethy malformation is a congenital extra-hepatic porto-systemic shunt. This malformation is characterized by an abnormal connection between the portal vein or its branches and one of the systemic veins. Though rare, this anomaly can lead to pulmonary hypertension. Drainage of Abernethy malformation into coronary sinus is extremely rare. We describe a child with Abernethy malformation with unusual drainage into coronary sinus. The abnormal channel was successfully closed by trans-catheter technique with normalisation of pulmonary arterial pressures.