In this article, thermal stability, viscosity, density and surface tension of Graphene nano-platelets dispersed sunflower oil are experimentally determined by varying the Graphene concentration (0.1-1.1wt%) and temperature (40-100?C). The SEM micrograph and the EDS spectra are used to characterize the Graphene. Nanofluids are prepared by ultrasonication technique (two-step method) and the maximum thermal stability of about 280?C is achieved at 1.1wt% Graphene nanofluids. The dynamic viscosity diminished in an exponential shape in acquiescence with Arrhenius equation and the densities of samples are characteristic with linear decrement in the estimated temperature range. Density and surface tension increases with the Graphene concentration, while a reverse trend is observed with temperature rise. The maximum thermal stability, viscosity, density and surface tension is obtained in the nanofluid with 1.1 wt% concentration and the minimum is obtained in the nanofluid with 0.1 wt% concentration.