Growing amounts of research press releases submitted from an increasing number of universities and a shift in communication focus from a national audience towards a larger international public, are changes we can register in science communication, but not explain with current models used in science communication research. By investigating similarities and differences between models of public relations on one hand and models of science communication on the other, this paper presents a solution to that challenge. In a model proposed by Van der Sanden and Meijman, science communication is understood as an activity described by its form and its function. The model operates with four functions: public understanding of, public awareness of, public engagement with and public participation in science. This paper shows how a fifth function – public relations in science – can be included in this model by using Grunig and Hunts four classic models of public relations. We thereby may be able to understand research press releases as both instruments to market universities and instruments that contribute to educating the public. The results are discussed by use of Grunig‟s mixed motives model.