This thesis presents the research on designing a decision support system for designing communication strategies. The importance of this topic comes from the idea that more academic knowledge from social sciences could be used in designing communication strategies. However, often those strategies are not designed by scholars. Therefore a way must be found to transfer knowledge from the academic field to practice. In this thesis it is believed that this can be done with help of a decision support system. The results of this thesis are guidelines on how to design such a decision support system. The theoretical framework of the design exists of three main topics. Design science, decision making and decision support systems. The first is addressed to become acknowledged with the way in which professional designers work. Most important findings are that especially in ill-defined problems the design process is not straightforward, switching between problem and solution occurs often. Furthermore a design is based on the stance of the designer, separate designers create different solutions to similar problems. Next, it was inquired how decisions are made and which parts of decision making could be supported. Thorough decision making is a very tedious and cognitive effort demanding task. Humans tend to shorten the decision process - consciously and unconsciously - by using all kinds of simplifications. It is expected that professional decision makers are more able to make tedious decisions, but still short-cuts in behaviour are found. As third, from the field of decision support system is found which systems already exist and which kinds of problems they address. Until now, not many systems have been designed to work in ill-defined areas like communication strategy design. The decision support system was designed by some of the intended end users under supervision of the researcher. The Public and Communication Department of the Dutch government, which arranges all government communication also found that using academic knowledge could improve the effectiveness of their campaigns. Therefore, they issued a request to two social scientists to write a body of knowledge specific for their needs. This is called the Communication Development Model [30]. For this research this was ideal, as a body of knowledge was needed as knowledge of the decision support system and participants were needed to design the system. Both were found at the Public and Communication Department of the Ministry of General Affairs. During several workshops the participants designed the system according to their needs. Care was taken by the researcher that the discussion was on a level which could be understood by non-computer specialists. Three main workshops were organised: during the first workshop the participants expressed their ideas by drawing on post-it notes and other paper; for the second workshops these ideas were translated to a paper prototype of the decision support system, this prototype was discussed with all participants; these ideas were implemented in a software prototype for the third workshop. The results from this last workshop were used to build a final prototype. However, it is not the prototype that is the result of this research but the guidelines that are found in the design process. Guidelines specifically for the design of decision support systems for designing communication strategies. Five guidelines have been stated as conclusion of this research: involve the user in the design, show the complexity of the task, give support not answers, enforce justification of decisions and keep the work area small.