To diminish wear in tribological systems it is not always necessary to provide the entire surface with a wear resistant layer. Depending on the application it is sufficient to harden locally the load carrying areas which are subjected to wear. Such areas can be treated properly by a laser, either totally or partially. This paper describes the effects of laser line hardening on the wear behaviour of carbon steel AISI 1045 against ball bearing steel AISI 52100. It is shown that the wear resistance of carbon steel AISI 1045 can be improved considerably by line hardening the surface. The wear resistance of the laser line hardened surfaces is comparable with that of carburised steel AISI 1045. However, the properties of the laser line hardened areas determine the wear behaviour of the entire system. Furthermore, the experimental work indicates that the type of heat treatment, carried out prior to line hardening in order to improve the microstructure of the steel, has no significant effect on the wear behaviour of the tribological system.