This chapter reviews the degradation mechanism and refurbishment technologies available for refurbishment of turbine components in power plants. Thermal components in gas turbines such as turbine blades, combustion liner, transition piece, shroud block, nozzles, fuel nozzle, swirler and cross fire tubes and steam turbine components that undergo severe damage due to operation in extreme condition. The current practice of refurbishment work for these components such as welding based repair, laser cladding, thermal spray and casting work have been discussed. The chapter also covers common damage and failure mechanisms that gradually deteriorate the performance of gas turbine over time. Challenges and industry limitations also have been discussed to allow further improvement of refurbishment works on the next level of turbine for sustainability.