In over 250 operative procedures in 135 cases the median nerve was subjected to a close study in the carpal tunnel. In 13 cases modifications of its regular branching were found. These variations have been described together with those reported in the literature. A double motor branch (6 cases) and a high division of the median nerve (4 cases) were the most common. In very few cases an accessory motor branch was found to leave the nerve proximal to the carpal tunnel.