Cubic aluminium nitride (AlN) coatings were successfully deposited on stainless steel 304L substrates by balanced magnetron sputtering. Grazing incidence X-ray diffraction measurement confirmed the formation of rock salt cubic AlN having a preferred orientation along (111) plane. Scanning electron microscopy revealed nodular microstructure of the coating. Thermal diffusivity of AlN coated sample was found to be significantly higher than that of the uncoated sample. Microscratch adhesion test showed no adhesive failure below 20 N loads.