Intense heat transfer is one of the paramount requirements (necessities) in many commonplace technologies used in industries that can only be fulfilled through phase change of cooling fluid. Most engineering systems such as power plants deal with pertinent boiling issues. Hence, many techniques to ameliorate boiling heat transfer have been presented and studied. Thanks to recent advances in nanotechnology, a new generation of fluids, nanofluids have come to existence. Nanofluids can increase heat transfer rate compared with conventional fluids like water, ethylene glycol and oil. Therefore, boiling characteristics must be taken into account when using them as cooling fluids. It is of significant importance to know nanofluids behavior under such circumstances to avoid corollaries that may negatively affect their cooling properties. Given the aforementioned reasons, the scrutiny of boiling heat transfer characteristics of nanofluids is of top priority at this stage. To this end, the present experimental study aims to investigate the film boiling heat transfer on high temperature cylindrical silver (10 mm in diameter and 100 mm in length) in nanofluid and water. In the present study, the temperature history in the center of cylinder is accurately recorded. Heat transfer rate from cylinder to fluid is calculated. Inverse heat transfer is used with the hypothesis of isotherm cylinder. The hypothesis was investigated using theoretical and experimental data and the results verified the hypothesis. Two cylindrical silvers with different surfaces roughnesses were used to investigate the effect of roughness on nanofluid boiling heat transfer. The surface roughnesses were measured by AFM yields 129 nm and 690 nm for smooth and rough surfaces respectively. The results gains suggested that a minimal differences in surface roughness leads to a substantial differences in quenching time of cylinders. In this study CNT- water, C-water, Ag- water and Fe 3 O 4 - water nanofluids were utilized. An almost all cases heat transfer rate was lower compared with the deionized water. This phenomenon is determined by particles material, particles deposition on boiling surface, surfactant and concentration of nanofluids. In order to investigate particle deposition on boiling surface before and after CNT nanofluid tests, SEM photos were taken from boiling surface. In Ferro fluid, the effect of magnet field on boiling heat transfer rate was surveyed. The distribution of magnet field was then simulated by Femm software and it’s pertinent the particle motion was monitored by PIV. Results indicated a considerable increase in boiling heat transfer. Keywords Boiling; Nanofluid; Roughne CNT-water; magnet field