A significant number of biological processes occur at, or involve cellular membranes, including; cell adhesion, migration, endocytosis, signal transduction, and many biochemical reactions involving membrane anchored scaffolds. Each process involves a complex arrangement of interacting molecules whose location in space and time influence the outcome of the event. In this protocol we discuss the application of fluorescence recovery after photobleaching (FRAP) to study the dynamics of membrane associated molecules. We discuss the principles, acquisition and the analysis of FRAP data and address issues surrounding its interpretation.