This paper deals with a numerical investigation of the film cooling effectiveness on five different curved surfaces and a flat surface. The models consist of 11 rectangular cross-sectioned injection holes aligned in a single row. The blowing ratios are from 0.5 to 2.0, and the injection angle with respect to the horizontal plane is 30 degrees. The hole geometry, the slope of the curved surface and the blowing ratio have important effects on the film cooling effectiveness. The results show that the film cooling effectiveness of a given curved surface, both along the mainstream and the spanwise direction, depends on the optimum selection of the parameters mentioned above. (c) 2005 Elsevier Ltd. All rights reserved.