An arteriovenous fistula may be defined as a vascular abnormality in which there are one or more direct or indirect communication between an artery and a vein without any intervening capillary bed. Largely, such fistulas are divided into two groups-acquired (traumatic) or congenital in origin. There is a general agreement that congenital A-V fistula results from a failure in differentiation of the common embryonic anlage into true artery and vein. The authors have experienced a case of congenital A-V fistula formed in the 4th finger of the left hand. Such fistula is very difficult to excise completely with the conventional method. But we have obtained the excellent result by utilizing advanced meticulous microsurgical technique in excision.