Enzymes produced by Thermus thermophilus are of considerable biotechnological interest. This review covers industrial applications of several protein products of this thermophilic bacterium that are functional under extreme conditions. The purification of proteins from T. thermophilus using either conventional methods or in the light of the cloning of their genes and expression in mesophilic microorganisms is discussed. Enzymes that biodegrade proteins, polysaccharides or key enzymes that are involved in amino acid metabolism, protein folding or in other fundamental biological processes such as DNA replication, DNA repair, and RNA maturation, with potential use in different biotechnological processes are reviewed as well.