Heat Pipe are the superconductors of heat because of their fantastic heat handling and transporting ability with minimum heat loss. A lot of research and experimentation has been carried out on heat pipes in the 21 st century due to modernization and miniaturization of equipments. This review aims to collect and compile research works by various authors in the field of heat pipe, where they have studied the performance of heat pipe under different tilt angles or inclinations. Gravitational and capillary forces play a very important role in deciding the overall performance of a heat pipe. At every different inclination, the resultant of these two forces varies, so the efficiency of a heat pipe also varies. This is the reason why there is a need to thoroughly study the performance of heat pipes at different inclinations.