Though the tribological properties of PVD TiN coatings have been extensively documented and are fairly well understood, this is not the case for ZrN coatings. Recent investigations have indicated that ZrN has great potential for protective coatings in many aeroengine components and also for specialised cutting tools. In view of this, the tribological behariour of ZrS coatings has been characterised on a mild steel substrate. ZrN coatings, approximately 10 μn thick, were produced on a steel substrate by reactive ion nitriding. The microstructures of the coatings were characterised by SEM while the phase distribution was examined using XRD. Coating hardness was measured using a Shimadzu ultramicrohardness tester. The tribological behaviour of ZrN was studied and compared with that of the steel substrate. The solid particle erosion resistance and abrasive wear resistance of ZrN were evaluated and compared with those of the substrate using a room temperature erosion rig and a rubber wheel abrasive tester, respectively. © 1997 The Institute of Materials.