The fatigue life reduction caused by fretting corrosion was determined in comparative fatigue life tests for axially loaded flat specimens made of GGG 40 (cast nodular iron, ASTM A 536-80: 60-40-12) and of St 34-2 (hot rolled structural steel, ASTM A 283-78: Grade C). A special test rig was constructed for superimposing fretting corrosion onto constant amplitude and spectrum loading of the specimen. Various surface conditions and two levels of surface pressure were investigated. Using the results of these tests and the parameters derived, comparative damage calculations were performed aiming at predicting fatigue life in the presence of fretting corrosion. Means to avoid fretting corrosion were also explained.