Percutaneous A1 pulley release was performed on 17 fresh-frozen cadaveric hands with a 14-gauge angiocath needle. Each hand was then explored to assess the adequacy of release and the degree of injury to adjacent structures. Complete release of the A1 pulley was obtained in 45 of the 66 fingers and in 10 of the 17 thumbs. Significant injury to the flexor tendons was observed in two digits. All tendon injuries occurred along the line of the fibers. There were no digital nerve injuries. The release was within 2 mm of a thumb digital nerve in seven hands and the little finger ulnar digital nerve in two. In the thumb, the close proximity of the digital nerves makes percutaneous trigger digit release potentially hazardous. With the little finger held in abduction the risk of digital nerve injury or inadequate release is reduced. Percutaneous trigger finger release can be safely performed in the index, long, and ring fingers.