A retrospective, continuous clinical series of 36 distally based posterior interosseous island flap procedures is reported. Major anatomic variations precluded the final dissection of the flap on two occasions (6%). Thirty-four patients had septocutaneous or septofascial flap coverage for treatment of acute complex injuries (12), subacute soft tissue defects (10), chronic ulcers (5), or contractures (7). The sizes of the flap islands varied from 1.5 by 4 centimeters to 9 by 11 centimeters. The arc of rotation, centered over the distal radioulnar joint, measured up to 19 centimeters, allowing the flaps to reach the dorsum of the proximal interphalangeal joints. Partial necrosis occurred in seven flaps; four (12%) required additional local or distant flaps. Partial failures were related to bleeding from the pedicle or compression thereof, while other assumed causes of hypoperfusion were not statistically relevant. The flaps remained slightly bulky in about 30% of the patients, but otherwise adapted well to the recipient site and had excellent texture and color match. The donor morbidity was minimal.