A man aged 33 years developed an arterio-venous fistula following a gunshot wound from behind in the right calf. The quality of the fistula could be demonstrated employing digital subtraction angiographic technique while the quantity was demonstrated employing 99Tc macroaggregated albumin. The localization of the fistula is important in view of the surgical procedure and the haemodynamic amount is important to determine cardiac involvement.