The paper presents the effect of pre-heat treatment on the mechanical properties of ductile cast iron with elevated content of Cu and Mo elements. Austempered Ductile Iron is a material with non-standard properties, combining high tensile strength and abrasion resistance with very good plasticity. In addition, it is prone to strain hardening and have good machining abilities. The study was conducted for five designed heat treatment cycles. The variables were the time and temperature of the pre-heat treatment, followed by one of two standard heat treatments for ADI cast iron. The aim of the authors was fragmentation of the grains of perlite during the initial heat treatment. It is presumed, that subsequent heat treatment will cause further refinement of the microstructure than would be the case without initial heat treatment. Diffusion is much faster than in case of ferritic matrix of cast iron. The results will be used to evaluate material for the production of parts of equipment that must operate under extreme load conditions.