The papers contained in this proceedings were presented at the symposium, Fourth International Conference on Very High Cycle Fatigue (VHCF-4), held at the University of Michigan, Ann Arbor, Michigan, USA, August 19-22, 2007. The objective of VHCF-4 was to provide an opportunity for the global fatigue community to present and discuss the latest experimental and theoretical research on the fatigue behavior of structural materials in the very high cycle regime. Specific topics covered include: Microstructure Initiation Mechanisms, Survace vs. Subsurface Initiation Advanced Materials and MEMS Influence of Notches and Surface Conditions Recent Advances in Apparatus and Instrumentation Life Predictions, Uncertainty and Statistical Analysis Influence of Environment and Temperature This proceedings facilitates the understanding of the fundamental mechanisms of fatigue in the VHCF regime, correspondingly, for the exploration of novel methods for the characterization of fatigue behavior at these very long lifetimes. A collection of papers from the Fourth International Conference on Very High Cycle Fatigue held at the University of Michigan in Ann Arbor, August 19-22, 2007.