The article explores the role that Polish business clusters play in the transfer of knowledge and innovation from science to business. It also identifies the forms of such cooperation at individual stages of cluster functioning. The discussion shows that the forms of knowledge and innovation transfer from research centers to enterprises are changing with the development of clusters. This conclusion is based on an analysis of available literature as well as on the findings of empirical studies. The article describes individual stages of cluster development and their role in the process of knowledge and technology transfer. The author evaluates the scope of collaboration between research centers and enterprises working as part of clusters. According to respondents, collaboration with the science sector enhances the technological advancement of businesses and boosts their competitive advantage. Despite these obvious gains, however, such collaboration is still limited in Poland, the author says.