Adsorption and hydrogenolysis of cyclohexylamine (CHA) on the Ni(100) surface have been characterized using temperature-programmed reaction spectroscopy (TPRS) and X-ray photoelectron spectroscopy (XPS). Cyclohexylamine interacts with the surface primarily through both the amino group and one carbon in the cyclohexyl group below 240 K. Substantial hydrogenolysis of adsorbed CHA is observed even in the absence of external hydrogen as the result of disproportionation to form ammonia (365 K) and benzene (465-480 K) during a TPD cycle. In the absence of external hydrogen, dehydrogenated residues are also observed above 500 K. External hydrogen pressures rapidly enhance the hydrogenolysis of CHA resulting in complete hydrogenolysis of a monolayer of adsorbed CHA for hydrogen pressures as low as 10(-5) Torr with no residual carbon or nitrogen remaining on the surface.