This paper reviews the literature on quantitative modelling for research and development (R&;D) project selection and resource allocation. The topic has been a subject of operations research for about four decades. Its importance stems from the fact that R&D projects are a core element of corporate renewal, heavily influence a firm’s market success and, if not properly chosen and trimmed, may waste large amounts of resources or even ruin the enterprise. Our survey classifies and characterizes the various modelling approaches.