CoNbZrN amorphous films were found to exhibit soft magnetic properties when deposited by ion beam sputtering or dc magnetron sputtering. In contrast to CoNbZr films they crystallize into a microcrystalline phase. Good magnetic softness is maintained during heat treatments up to 700 °C. It was found that the crystalline phase includes Co and NbN fine grains. The results of magnetostriction and electrical resistivity measurements suggest that an initial stage of crystallization starts at relatively low temperatures.