Local and average heat transfer coefficients were measured in a test section simulating a rib-roughened trailing edge cooling cavity of a turbine airfoil. The rig was made up of two adjacent channels, each with a trapezoidal cross sectional area. The first channel supplied the cooling air to the trailing-edge channel through a row of racetrack-shaped slots on the partition wall between the two channels. Eleven cross-over jets, issued from these slots entered the trailing-edge channel, impinged on eleven ribs, made a 90-degree turn and exited from the end of the trailing-edge channel. Tests were run for the baseline case of smooth target wall as well as four angles of attack between the axial flow and the ribs (0°, 45°, 90° and 135°). Cross-over jet axis made a zero-degree angle with the trailing-edge channel center-plane. Jet Reynolds number was varied from 10,000 to 35,000. The numerical models contained the entire trailing-edge and supply channels with all slots and ribs to simulate exactly the tested geometries. They were meshed with all-hexa structured mesh of high near-wall concentration. A pressure-correction based, multi-block, multi-grid, unstructured/adaptive commercial software was used in this investigation. The k–ω with Shear Stress Transport (SST) turbulence model was used for turbulence closure. Boundary conditions identical to those of the experiments were applied and several turbulence model results were compared. The numerical analyses also provided the share of each cross-over hole from the total flow for different rib geometries. The major conclusions of this study were:a) Both measured and numerically-obtained results show that the local Nusselt numbers correlate well with the local jet Reynolds numbers, b) 90° rib arrangement, that is when the cross-over jet axis was parallel to the rib longitudinal axis, produced a higher heat transfer coefficient, and c) Numerical heat transfer results were generally in good agreement with the test results. The overall difference between the CFD and test results was about 10%.