Good knowledge of literature is a desirable competence among children's librarians, and it is said to require constant environmental scanning. At the same time, there is often a lack of time and opportunity for skills development in this area. The aim of this thesis is to examine how children's librarians build up their knowledge of literature, what significance it has and what factors affect them in their environmental scanning of children's literature. Empirical data were produced through interviews with five librarians working with children aged 0-12 as their target audience. The data were analyzed by employing Bates’ model of four different information-seeking modes. The results show that all four modes are vital for environmental scanning. The importance of literature knowledge is confirmed in descriptions of how they use their literature knowledge. One conclusion is that children's librarians' knowledge of literature is based more on personal and professional experience of children's literature than on literary studies. Bibliotekstjänst and colleagues are important channels for environmental scanning. Another conclusion is that children as a target audience demands more of an active – directed information seeking than adults.