An experimental study has been carried out for jet impingement cooling on a semi-circular concave surface when jet flows were ejected from three different slot nozzles-round shaped nozzle, rectangular shaped nozzle and 2D contoured nozzle. Experiments have been conducted with variations of nozzle exit Reynolds number (Re-2B) in the range of 5920 less than or equal to Re-2B less than or equal to 25500 and nozzle-to-surface distance (z(n)) in the range of 1/2 less than or equal to z(n)/B less than or equal to 20 to determine the heat transfer coefficients under a constant heat flux condition. The developing structures of free jets were measured by hot-wire anemometer to understand the characteristics of heat transfer in conjunction with measured jet flows. Markedly different flow and heat transfer characteristics have been observed depending on different nozzle shapes. Average heat transfer rates for impingement on the concave surface are found to be more enhanced than the flat plate results due to the effect of curvature. Comparisons between the present results and the existing experimental results have also been made.