This paper applies a model including back-propagation network (BPN) and principal component analysis (PCA) to compute the effective thermal conductivities of nanofluids such as Al2O3/(60:40)EG:H2O, Al2O3/W, Al2O3/(20:80)EG:W, Al2O3/(50:50)EG:W, ZnO/(60:40) EG:W, CuO/(60:40)EG:W, CuO/W, CuO/(50:50)EG:W, TiO2/W, TiO2/(20:80)EG:W, Fe3O4/(20:80) EG:W, Fe3O4/(60:40) EG:W, Fe3O4/(40:60) EG:W and Fe3O4/W, as a function of the temperature, thermal conductivity of nano particle, volume fraction of nanoparticle, diameter of nanoparticle and the thermal conductivity of base fluids. The obtained results by BPN-PCA model have good agreement with the experimental data with absolute average deviation and high correlation coefficients 1.47 % and 0.9942, respectively.