The structure and properties of Co‐N, Co‐Fe‐N, and Co‐Zr‐N films, prepared by rf reactive sputtering using nitrogen and argon gases, have been studied. The resistivity and coercivity of Co‐N, Co‐Fe‐N, and Co‐Zr‐N films were determined as a function of nitrogen partial pressure. It was found that the properties of Co‐N and Co‐Fe‐N films were very similar where the properties were determined mainly by the nitride phases in these films. The resistivity of both Co‐N and Co‐Fe‐N films increased with the increase of nitrogen pressure. The coercivity of both films decreased with an initial increase of nitrogen pressure, then increased with a further increase of pressure so that there is a region of nitrogen pressures where the coercivity is at its lowest value. The low coercivity is attributed to the formation of the Co4N phase in Co‐N films and both Co4N and Fe4N phases in Co‐Fe‐N films. For Co‐Zr‐N films, resistivity first decreased with an increase of nitrogen pressure, then increased with a further increase of pressure, indicating the presence of a Zr‐N phase in these films. The coercivity increased with an increase of nitrogen pressure. The Zr‐N phase was not observed in the x‐ray diffraction measurements due to the low concentration of Zr in these films.