The aim of this study is to examine how school librarians and teachers look upon collaboration between their professions in reading promotion projects, trying to identify challenges and opportunities and important views school librarians and teachers have on each other's profession. The questions the study tries to answer are:  What opportunities for collaboration in reading promotion projects do school librarians and teachers see? What challenges for collaboration in reading promotion projects do school librarians and teachers see? What views of the different professions are made visible in the reasoning of school librarians and teachers? The method used in the study is interviews with school librarians and teachers. The analysis is based on the theory of collaborative dimensions presented by Folkesson: the professional dimension (professional identity and professional culture); the power dimension; the legitimacy dimension. The results of the study shows that both teachers and school librarians believe that long-term planning is key to create good cooperation, but lack of time and the teacher's more scheduled working day becomes an obstacle. Both professions express a clear view of each other's competencies that is characterized by respect and trust, but also describes the roles a bit stereotypically. Both professions think the principal's commitment and participation is very important for legitimizing the school librarian's role in school work.