Of 74 patients with extensive skin loss of the upper and lower extremities who were treated with free skin flaps, 20 patients presented with venous insufficiency within the immediate 6 to 12 hours following surgery. In 17 of these patients, the venous congestion after free tissue transfer was successfully treated with medical leeches. The remaining three skin flaps did not survive, despite leeching, as well as exploration and revision of the venous anastomoses. The results from this small number of patients with free skin tissue transfer are encouraging, suggesting that in the presence of venous congestion, the use of medicinal leeches is a desirable modality of treatment.