The purpose of this numerical study is to investigate the effect of using nanofluid on the thermal performance of a single phase natural circulation mini loop (SPNCmL) in inclined conditions, for the first time, by using a three dimensional steady numerical model. The steady numerical study was carried for different heater powers (10, 30, 50 W), volumetric concentrations of Al2O3-DIW nanofluid (1, 2, 3%) and inclination angles (0, 30, 60, 75 degrees). A recent experimental study has been adopted from the existing literature to compare the results of the numerical method. The results indicate that, steady numerical model can predict the reaction of the SPNCmL to particle concentration, heater power and inclination angle sufficiently. The deflection (not more than 10%) from the experimental results increases as the heater power, particle concentration and inclination angle increase. Simulation results are used to visualize temperature distributions at the critical cross-sections of the loop for different working fluids, inclination angles and heater powers. Visualized temperature distributions highlight the necessity of improvement for the investigated SPNCmL. Therefore, steady three dimensional numerical studies can be used to properly define the local defects and to increase the efficiency.