Offshore wind energy (OWE) is one of the emerging sustainable energy sources that are currently developed under public support. In the long run, it needs to become competitive in the energy market under the same conditions as regular sources, and it is expected that engineering design can contribute significantly towards this goal. Various activities, both academic and industrial, have contributed to the knowledge base that is needed for design and technology development and the paper reviews this knowledge. The objectives of the paper are to identify points of attention for future research and to suggest directions where academic research can contribute to design improvements. The review and the suggestions do not address very specific areas of the broad range of knowledge, but rather characterizes the types of knowledge that are available and which are missing. Many research activities contribute to foundational knowledge, needed to perform simulation and analysis of provisional design solutions. Most of the design-related studies reviewed for this paper are solution oriented and contribute to contextualized knowledge. Studies that put more emphasis on methodologies largely target optimization methods. Existing knowledge appears to be weak in methodological support of the integration of the various asynchronous design processes that contribute to OWE development. The paper leads to a plea to generate such knowledge, which can be transferred from academia to industry to enhance the design strength already present in the industry. Several points of attention are given for this type of research. Copyright © 2009 John Wiley & Sons, Ltd.