Experimental investigations were performed on Al2O3-H2O nanofluids using split flow type microchannels with particle volume fractions of 0, 0.1%, 0.25%, 0.5% (vol.) with the flow rate ranging from 0.5ml/min to 2.0ml/min. The effect of Prandtl number and Reynolds number is also studied. Experimental results show that thermal conductivity increases and viscosity decreases with increase in temperature. Thermal conductivity and viscosity increases with increase in concentration of nanofluids. Heat transfer coefficient, Prandtl number. It is seen that heat transfer coefficient and Prandtl number increases with increase in concentration of particles whereas Reynolds number decreases with increase in concentration. The heat transfer coefficient increased by maximum of 27% for 0.5% (vol.) concentration and Prandtl number increased by 22% maximum. However Reynolds number had decreased by maximum of 28% for 0.5ml/min flow rate and least decrease by 18% for 2ml/min flow rate.