Separation of oils from solid surfaces is important in cleaning and degreasing operations. Water and oils are immiscible requiring the use of an additive which is miscible with water yet has an affinity for oils. Surface active agents, known as surfactants, have this property, being miscible with water while having an affinity for hydrocarbons. In some cases, surfactant solutions displace oils from a solid surface (i.e., remove oil by replacing the oil/solid interfacial area with surfactant solution/solid interfacial area). The presence of alkalinity as well as surfactant concentration is known to affect the ability of a surfactant solution to wet the solid surface and displace the oil. Experiments have been performed to determine quantitatively the effects of surfactant concentration and pH on the displacement of an oil from a metal surface. The displacement is measured in terms of the contact angle formed by the oil on the solid surface in the presence of the surfactant solution, the amount of time needed for the surfactant solution to cause part of the oil to detach from the solid surface, and the volume of the detached oil. Measuring the contact angle of the oil as a function of time shows that surfactant concentration and pH affect the displacement of oil from a metal surface. Increasing the pH of a solution of Triton X-100, a non-ionic surfactant, enhances oil displacement. Increasing the surfactant concentration also enhances oil displacement. The volume of oil which detaches from the solid surface increases with increasing pH and increasing surfactant concentration.