Abstract Introduction: Teachers in Finland are demanded to develop students’ competencies in information literacy. However, they can meet this demand only by collaborating with public librarians. The aim in this case study was to explore the perspectives of teachers, librarians and students in a problem-based project and to analyse the advantages and challenges of collaboration between teachers and librarians. Methods: Teachers and librarians together designed and implemented a learning project in a secondary school, where triangulation of data collection took place: group interviews with four teachers and two librarians and a questionnaire for forty students. Analysis: The interviews and questionnaires were categorized and analysed by means of qualitative content analysis, using QSR NVivo 10. The categorization followed theory-based procedures. Results: The study reveals that collaboration between teachers and librarians was rewarding, especially in joint teaching situations. Challenges were related to lack of planning time, students’ diverse skill levels and, to some degree, to the unclear roles of teachers and librarians. The study resulted in a model for integrating information literacy with problem-based learning. Conclusion: The new model produces new understanding of the characteristics and critical points of the collaboration and clarifies how information and communications technology (ICT) can be used to support student-centred, problem-based learning processes facilitated and instructed by teachers and public librarians located in physically separated places.