Recently, coastal investigators have questioned the function of barrier dunes during storm conditions. Dunes were believed to interfere with swash processes by constricting the beach profile over which the energy must be dissipated. Also, some researchers believed that dunes act as seawalls and reflect a significant portion of the incident wave energy. Either of these two possible effects would result in accelerated beach erosion. Considering the worldwide importance of coastal dunes as a protective barrier system, it was paramount to gather information by which to further examine these hypotheses. In this paper, the author reports field data collected to date during storm conditions and summarizes the pertinent laboratory investigations. Finally, a new model is conceptualized regarding the functioning of barrier dunes during storms versus flow dissipation by overwash.