An efficient and high-yielding method for the preparation of optically pure (S)-(+) -10,11-dihydro-10-hydroxy-5H-dibenz/b,f/azepine-5-carboxamide and (R)-(-)-10,11-dihydro-10-hydroxy-5H-dibenz/b,f/azepine-5-carboxamide by resolution of racemic (.+-.)-10,11-dihydro-10-hydroxy-5H-dibenz/b,f/azepine-5-carboxamide using a tartaric acid anhydride.