In this chapter we highlight the importance of appropriately valuing research and development investments. We identify specific characteristics of research and development projects, such as irreversibility, uncertainty and managerial flexibility. In Sect. 2.2 we suggest valuation tools that are able to take these characteristics into account in order to valuate projects in research and development. In Sect. 2.3 we present a case study. The case study analyzes the decision process in the development of the Siemens H-class Gas Turbine. It illustrates how companies make their decisions about research and development projects in practice.