There is described a turbine blade of a gas turbine comprising a suction-side blade wall and a pressure-side blade wall that, in the trailing edge area, runs toward the suction-side blade wall. This suction-side blade wall has a trailing edge projection projecting over the end edge of the pressure-side blade wall at least in a partial section of the trailing edge area. A turbine blade of the aforementioned type is designed for a particularly long serviceable life while requiring little cooling air. To this end, the pressure-side surface of the trailing edge projection has a number of trough-shaped recesses that increase the transfer of heat from the trailing edge projection by a local swirling of the cooling air.