Additive manufacturing enables the design of components with intricate geometries that can be manufactured with lead times much shorter when compared with conventional manufacturing. The ability to manufacture components out of high-performance metals through additive manufacturing technologies attracts industries that wish to develop more complex parts, but require components to maintain their structural integrity in demanding operating environments. Nickel-based superalloys are of particular interest due to their excellent mechanical, creep, wear, and oxidation properties at both ambient and elevated temperatures. However, relationship between process parameters and the resulting microstructure is still not well understood. The control of the microstructure, in particular the precipitation of secondary phases, is of critical importance to the performance of nickel-based superalloys. This paper reviews the additive manufacturing methods used to process nickel-based superalloys, the influence of the process parameters on microstructure and mechanical properties, the effectiveness of various heat treatment regimens, and the addition of particles in order to further improve mechanical properties.