Ammonium dinitramide (ADN, NH4+ N(NO2)(2)(-)) based monopropellants are extremely promising as hydrazine replacement. Thermal igniters are attractive for ADN thrusters as they allow a more prompt ignition and may be better suited for larger engines (100-500 N) compared to the currently used preheated catalysts. The results of an experimental campaign conducted on the ignition of two ADN-based monopropellants (LMP-103S and FLP-106) with a torch igniter are presented. Several combustion chamber configurations have been tested to facilitate the ignition. Through the use of porous inlays in the chamber, ignition of both propellants was achieved. It was not possible, however, to achieve sustained combustion under the chosen test conditions.