The fracture toughness of thermally sprayed WC-Co coatings of nominally identical composition, WC-17Co, produced by HVOF (High Velocity Oxy-fuel) process, has been studied using indentation technique. This method showed that these coatings exhibited anisotropic crack propagation and crack propagation was much easier parallel to the coating / substrate interface than transverse to it. Due to the high fracture toughness of these coatings, the optimum load to obtain suitable crack length for measuring the fracture toughness was found to be 20 kgf As a result, relatively very thick coatings (600 mum) were needed to be able to measure fracture toughness. This study also showed that by increasing the loading time in this method, the variation of crack length was limited and the standard deviation of fracture toughness values was reduced.