We observed diatomic hydrogen and nitrogen desorbing from Pt(111) surfaces covered with multilayer ammonia at 120 K during electron irradiation at 600 eV. Experiments were conducted to verify that the source of H-2(g) and N-2(g) species was indeed the electron-irradiated ammonia multilayer. This effect, which we describe as electron-stimulated associative desorption (ESAD),has not been previously reported.