An in–house Fortran based two-phase Eulerian-Eulerian solver is used to numerically study an incompressible confined slot jet impinging with nanofluid on an iso-thermal hot flat surface of a mini channel in the laminar regime. The governing equations of liquid and solid phases are solved using finite difference method. Heat transfer performance of water-based nanofluid with different nanoparticles such as Al2O3, SiO2, Cu, Fe, diamond and Ag is studied. Heat transfer performance of nanofluids cannot be predicted solely from the thermal conductivity values of suspended nanoparticles as observed that Al2O3 water nanofluid shows better performance than iron-water nanofluid. Since the iron-water nanofluid has only 5% more average Nusselt number but 7% more pressure drop compared to Al2O3-water nanofluid for jet Reynolds number 300 and particle concentration 5%. Heat transfer performance of Cu-water nanofluid is studied and reported for different parameters such as jet Reynolds number, particle concentration and channel height to jet width ratios. Results show a significant change in heat transfer characteristics with respect to jet Reynolds number, particle concentration, and height to jet width ratio. The heat transfer enhancement is 25% for Al2O3 water nanofluid and 60% for Cu- water nanofluid compared to pure water at jet Reynolds number 300 and particle concentration 5%. An empirical correlation is developed to predict the average Nusselt number of the jet flow with Cu-water nanofluid impinging on a hot surface. Present results are validated with numerical and experimental results available in the literature. © 2020 Elsevier Ltd