The aim of this study is to gain insight into how school librarians work with reading promotion activities directed to boys in schools. The two main purposes are to study how the interviewed school librarians’ work with reading promotion directed to boys and how they approach challenges that arise in this work. The methods used in this study are semi-structured interviews and a qualitative content analysis. Six school librarians were interviewed, of which five work at upper secondary schools with mainly boys in vocational programmes and in university preparation programmes. The remaining school librarian works at a compulsory school and conducts reading projects especially directed toward boys. To analyse the interview responses, six of Gambrell’s seven rules of engagement were used. Zimmerman’s theoretical concept “traditional homosociality” and “reflexive homosociality” were used to analyse reading projects and reading male role models. According to the results of the current study, the interviewed school librarians use six of Gambrell’s seven rules of engagement to motivate boys to read. They use book discussions, book tips, class reading with books of the boys own choices, book purchases according to the boys’ interests and they acquire a wide selection of books in the school library to motivate boys to read. Challenges that arise in the school librarians’ reading promotion work are reluctant and struggling readers among the boys. The school librarians use reading male role models and organise projects with books dealing with ethical issues to counteract boys’ peer pressure and negative attitudes, according to which reading is regarded as feminine behaviour. In this way the interviewed school librarians strive to increase boys’ reading motivation.