In the last decade thermophotovoltaic (TPV) generator has gained an increasing attention as cogeneration system for the distributed generation sector. Nevertheless, these systems are not fully developed and studied: several aspects need to be further investigated and completely understood.The aim of this study is to give a complete overview and the status of the art of thermophotovoltaic generation considering both the research developments and the experiences field. More in details, in this study, the characteristics of a TPV generator are analyzed with a particular attention to the physical relationships which govern the behavior of its main components. Moreover, the current technologies regarding the combustor, the emitter, the optical filter and the photovoltaic cells are investigated by taking into account both the role of each component and also their integration in the whole system. Finally, a critical review of the realized prototypes is presented and discussed