The effects of cyclic compressive forces upon the electrical resistances of steel-steel and copper-copper contacts were investigated. Under six sequences of increasing and decreasing cyclic loads at 40 Hz, a rise in the resistance of contacts between newly machined copper specimens and a fall in resistance of newly machined steel-steel contacts were observed. Evidence in favour of a hypothesis correlating surface roughness of the contacting surfaces with static contact resistance is presented. The contact behaviour is mainly dictated by the oxide films present.