This paper describes the different workplace cultures and accompanying professional values and behavior of university and public school partnership colleagues. It discusses the problems and successes of public school/university collaboration as documented in the research literature and relates those problems and successes to differences in workplace cultures. It shows how workplace cultural differences manifested themselves in a conflict regarding a course taught at the Winthrop University School of Education in which the middle school partners who enrolled were disappointed at being cast in a traditional learner's role when they perceived themselves as uniquely qualified by middle school experience. University faculty then realized that offering a traditional university course to professional development school colleagues was antithetical to shared decision-making. The foundation for effective professional development schools is an establishment of common cultural understandings and a willingness to work together. The partnership must value inquiry as a priority and allocate time and resources for this activity to occur. The paper speculates about the implications of these cultural differences for school-university partnerships that seek to create the professional development school as a "school of tomorrow." (Contains 20 references.) (JDD)