ABSTRACT The importance of exchangers in the competitive ambiance of different industries has been proven. One of the most widely used exchangers in the industry, especially in the oil and gas industry, is plate heat exchangers. The aim of this study was to enhance the heat transfer coefficient in plate heat exchangers using nanofluids. Al2O3/water nanofluid with different Reynolds number and nanoparticle volume fractions was applied. The problem geometry was produced using Solidworks and Gambit softwares and numerically solved using Fluent software. The plate heat exchanger consists of 10 plates with specified distances which arranged on top of each other. A single-phase and homogeneous nanofluid was considered. In the present work, the effects of volume fraction of nanoparticle, Reynolds number, Chevron angle, horizontal distance, and pitch length on the flow and heat transfer parameters have been investigated. The results revealed that the optimum conditions for heat transfer, pressure drop and the pumping power were obtained at 60°/60° Chevron angle, the volume fraction of 2% and the horizontal distance of 60 mm.