For the first time, an experimentally determined excitation function for tritium production from beryllium has been obtained. Beryllium samples were irradiated with well-known fluxes of monoenergetic neutrons in the 12.86- to 19.57-MeV energy range and the induced tritium was quantitatively extracted and counted. The results disagree with the JEF-1 prediction but show a remarkably good agreement with JENDL-3/PR2 and a recent Los Alamos National Laboratory evaluation, both based on 14-MeV values and theoretical calculations.