The combustion behavior of triaminoguanidine nitrate (TAGN) was investigated over a wide pressure range and a detailed combustion mechanism has been proposed. Temperature profiles in the TAGN combustion wave were measured with thin tungsten-rhenium microthermocouples. It was shown that the surface temperature in combustion of TAGN as well as for other onium salts is controlled by the process of dissociation. The burning rate of TAGN is governed by processes in the condensed phase.