A composite Langmuir-Blodgett film made of polyimide and polypyrrole that is thermally stable at elevated temperatures is reported. The composite, comprising alternating monolayers of polypyrrole and polyimide derived from polyamic acid-octadecyl amine salt, was made by a two-step polymerisation; 3-n-octyl pyrrole was polymerised by spreading it on aqueous ferric chloride. After LB film deposition, the composite was subjected to thermal or chemical treatment in order to convert the polyamic acid precursor to polyimide. For both imidisation methods, infrared spectroscopy showed the presence of polypyrrole in the polyimide matrix up to a temperature of 250 degrees C.