We present an anatomical and histomorphometric study of the transfer of the motor branch to the brachioradialis muscle to the anterior interosseous nerve in recent brachial plexus lesions, involving C8 and T1 roots. The aim of this study was to demonstrate the anatomic constancy of the nerves involved in the transfer, feasibility, and reproducibility of the transfer. We performed a study of 14 elbows in fresh cadavers. Transfer of the motor branch of the brachioradialis muscle to the anterior interosseous nerve was possible in all specimens; there was constancy in the origin and entry into the muscle of the donor nerve, and it was always possible to dissect the recipient nerve at the level of the donor nerve, thereby allowing for direct coaptation of the nerves. The mean diameter of the anterior interosseous nerve was 2.9 ± 0.5 mm and the mean diameter of the brachioradialis muscle branch was 2 ± 0.4 mm. The branch to the brachioradialis muscle contains an average of 550 ± 64 myelinated axons and the anterior interosseous nerve has an average of 2266 ± 274 myelinated axons. The anatomic study in cadavers showed that the technique is justified and anatomically reproducible. © 2012 Wiley Periodicals, Inc. Microsurgery, 2013.