Boiling heat transfer is one of the most applicable heat transfer processes within the industry.In this research, an experimental study was conducted to investigate the pool boiling heat transfer of Fe 3 O 4 /water nanofluid (ferrofluid) in the atmospheric pressure. The applied nanofluid within this research was synthesized through a single step to retain a high stability. The repeatability and precision of the testing device with deionized water show a well agreement with introduced equations of previous studies. Parametric studies on the magnetic field, surface roughness, and magnetic nanofluid concentration are performed to reveal various aspects of the boiling heat transfer. In order to study the surface roughness, two surfaces with high average roughness (480nm) and low average roughness (7.3nm) were used. In addition, experimental studies showed that the presence of positive and negative magnetic field gradients decreases and increases the boiling heat transfer, respectively. The findings of this study showed that at higher concentrations of nanofluid, the effect of the magnetic field on nanoparticles is boosted. The results of the experiments indicated that adding nanoparticles would not necessarily increase the boiling heat transfer coefficient. In fact, the surface roughness and the magnetic field gradient on the boiling surface were the main factors that could affect the boiling heat transfer coefficient, significantly. Moreover, the heat transfer of a nanofluid with volume concentration of 0.1% is greater for the rough surface compared with the smooth one. The simultaneous analysis of magnetic field, surface roughness, and nanofluid concentration reveals that the boiling heat transfer coefficient of the magnetic nanofluid with 0.1% volume concentration in the presence of a magnetic field on the rough surface is higher than smooth surface. Our findings show that this increase is associated to the increase of nucleation sites concentration and bubble formation sites for the rough surface. The roughness of boiling surface was varied with the deposition of nanoparticles in various conditions of nanofluid concentration, and heat flux. It is noteworthy that in the present research, the effects of surface roughness change due to nano particles deposition and the impact of passing time on boiling process have been investigated for the first time. Therefore, several experiments have been designed in order to study the change of nanoparticles deposition due to the change of nanofluid concentration and boiling surface heat flux. The results indicate that boiling heat transfer of deposited surfaces at low heat fluxes decreases, while it rises at high heat fluxes.