The work reported in this paper is an attempt to enhance heat transfer in electronic devices with use of multi air jet impingement on pin fin heat sinks with effusion slots on the nozzle plate. In this study the effect of nozzle jet exit velocity, heat sink array, and the height of pin fin on the average Nusselts number (Nua) are studied. Numerical investigation is carried out on multi air jet array of 3×3, 5×5 and 10×10(nozzle diameter 5, 3 and 1.5mm) impinging on aluminum pin fin heat sink (pin fin array 4×4, 6×6 and 11×11 respectively) for H/d ratio of 3, 4 and 5 keeping the nozzle exit to pin fin tip distance Id for each case. Numerical analysis carried out for the Reynolds number range from 11000 to 49000 for constant heat supply of 30W (Constant heat flux 8333W/m2). The results reveals that the at smaller H/d ratio heat transfer is more effective. Similarly the smaller the pin fin size, better the heat transfer performance of pin fin heat sink. The higher Reynolds number yields more heat transfer coefficient.