Some vegetable oils have electrical and thermal properties similar or better than those of current dielectric fluids with superior environmental performance. The intrinsic properties of natural vegetable oils in terms of fire resistance, environmental performance and electrical and thermal characteristics, dielectric compositions are particularly useful products in the field of electrical engineering. In this work, we report measurements of the viscosity and resistivity of the oils Argan, Olive, Avocado, Canola and Sunflower. These measurements show that viscosity and resistivity decreases when the temperature believed. This decrease was attributed to the effect of the thermal agitation of molecules on the structure of these oils.