Illustrated children's books, one of the most important educational materials in environmental education practices, provide children with an understanding of the environment, acquiring environmental awareness, seeing environmental problems, and developing solutions to existing problems. These books aim to be useful to children through the topics they cover and the subliminal messages they contain for the purposes of environmental education. The aim was to examine which topics had been covered in illustrated children’s books prepared with a view on environmental education and appropriate for the pre-school period and for which purposes the environmental education had been prepared. The study group of the study is comprised of 50 illustrated children’s books which have been determined with the criterion sampling from among purposeful sampling methods. The criteria determined for this study was that the books were prepared for environmental education and appropriate for the pre-school period. The illustrated children's books were examined by qualitative research methods using the document analysis method. The obtained data were analyzed by content analysis technique and it was determined which subjects the books cover for environmental education and for which purposes the environmental education had been prepared. In conclusion it has been determined that the majority of the 50 illustrated children's books examined in the scope of the study are inadequate in terms of telling children about the reasons for loving nature, environmental problems and why they must be prevented. Furthermore, it is believed that the examined books do not contain any topics that children can identify with being an environmentalist.