The solid-state reactions of Pt, Pd, and Ni thin film contacts on ZnSe were studied. Pd has been observed to react at 200 degrees C to form a ternary, epitaxial phase, Pds(5+x)ZnSe. This phase is stable up to 450 degrees C, when Pd begins to diffuse through the ZnSe into the GaAs substrate. Pt begins to react at 575 degrees C and forms a layer of Pt5Se4 at the Pt/ZnSe interface. Above the interfacial layer there is a Pt-Zn solid solution, but no Pt-Zn phases were observed. After annealing at 675 degrees C, the Pt5Se4 phase is no longer observed and Pt-Zn phases form. A small amount of interdiffusion at the Ni/ZnSe interface has been observed by transmission electron microscopy after annealing at 300 degrees C. Annealing at 425 degrees C results in the formation of laterally separated grains of a metastable NixSe phase. After annealing at 450 degrees C, grains of NiSe are observed. The similarities between these reactions and the near-noble metal reactions on Si and GaAs are discussed as well as the possibility of using these reactions for forming electrical contacts to ZnSe.