This thesis examines the way cooperation between the schools and   school libraries are described in the library plans in 21 of the municipalities in Sweden. Our selection has been based on geographical spreading. Our used method in this thesis is a content analysis, where both qualitative and quantitative methods have been used. In Sweden, primary school is mandatory and nine years ago it also became statutory for every school to have a school library. The law also says that the principal/head of the school has a responsibility to make sure a collaboration is even possible. Our research also shows that the principal's/head of the schools role is vital for how the collaboration will work. He or she can demand the staff to start working together or arrange for them to be able to get time to plan together. A number of research shows that it’s important with a collaboration between the schools and school libraries, the collaboration can improve the students' study results. It also highlights how the library plan can act as an important strategic document for the libraries. We have used Patricia Monitel-Overalls TLC-models (Teacher-Librarian-Collaboration) for our analysis. In our results we found that both the teachers and librarians often wanted to have a collaboration. Still, not many did and the most common reasons were that none of them really knew what to expect or demand of each other. Another reason was that the picture of what a library can offer and help with was very old fashioned. In other words, they did not know everything a librarian can do or how much the library could help. In conclusion, the library plans need to be more direct with how the schools and school libraries are supposed to work together. That includes both the collaboration, how everyone can communicate and who’s in charge.