Fibrin sealing, with or without sutures, has become a commonly used technique in human nerve grafting with clinically good results, but is seldom used in primary repair of peripheral nerves. A prospective study was designed to evaluate the incidence of dehiscence in the traditional (Tisseel Kit) and a new "ready-to-use" fibrin seal preparation (Tisseel Duo), and the outcome following fibrin sealing was compared with microsurgical repair of peripheral nerves in rats. No dehiscence was seen in the Tisseel Duo group compared with 20% in the Tisseel Kit group. The electron micrographic evaluation following regeneration showed no significant difference from the microsuture group. Tisseel Duo should therefore be used instead of the traditional fibrin seal preparation when no sutures are used, and may prove to be an alternative to microsuture of peripheral nerves.