The effect of the rf power on the structural and electrical properties of nanostructured silicon carbon films deposited by Plasma Enhanced Chemical Vapour Deposition system, using silane and methane gas mixture highly diluted in hydrogen, has been investigated. The structural and electrical properties are found to depend strongly on rf power. The increase of the rf power decreases the size of the silicon crystallites as well as the crystalline fraction and increases the carbon content in the films. The study not only indicates the correlation between crystalline fraction and the electrical conductivity but also reveals the presence of nanocrystallites in the films deposited at high rf power.