The current study investigated comparative performance of wall-confined and unconfined multiple micro-jet impingement heat sink models for electronic cooling applications. The pressure-drop and thermal characteristics were determined for steady incompressible and laminar flow by solving threedimensional Navier-Stokes equations. Several parallel and staggered micro-jet configurations consisting of a maximum of 16 jet impingements were tested. The effectiveness of various micro-jet configurations, i.e., inline 2×2, 3×3 and 4×4 jets, and staggered 5-jet and 13-jet arrays with nozzle diameters 50, 76, and 100 μm, were analyzed at various flow rates for the maximum temperature-rise, pressure-drop and heat transfer coefficient characteristics. Two design parameters, the ratio of jet diameter to height of the channel and jet distribution, were chosen for comparative performance analysis.