Manifold-microchannel technology has demonstrated substantial promise for superior performance over state of the art heat exchangers, with potential to reduce pressure drop considerably while maintaining the same or higher heat transfer capacity compared to conventional microchannel designs. However, optimum design of heat exchangers based on this technology requires careful selection of several critical geometrical and flow parameters. The present research focuses on the numerical modeling and optimization of a manifold-microchannel plate heat exchanger to determine the design parameters that yield the optimum performance for the heat exchanger. A hybrid method that requires significantly shorter computational time than the full Computational Fluid Dynamic (CFD) model was developed to calculate the coefficient of performance and heat transfer rates of the heat exchanger. The results from the hybrid method were successfully verified with the results obtained from a full CFD simulation and experimental work. A corresponding multi-objective optimization of the heat exchanger was conducted utilizing an approximation-based optimization technique. The optimized manifold-microchannel plate heat exchanger showed superior heat transfer performance over chevron plate heat exchanger designs. (C) 2014 Elsevier Ltd. All rights reserved.