The purpose of this study was to develop a checklist whose validity has been tested in assessing children's books. Participants consisted of university students who had taken a course in children's literature. They were selected through convenience sampling and randomly assigned into experimental and control groups. Participants in the experimental group were exposed to quality books based on the criteria of appropriateness for children which were developed by Çer and Sahin (2016, Appendix A), whereas those in the control group were exposed to non-quality children's books. Both groups learned how to use a checklist in order to assess the books. The experimental group's evaluation of the design, contents, and instructional qualities of the books was significantly higher than that of the students in the control group for all dimensions. Thus, it is possible to assess children's books through this checklist whose validity has been proven. Moreover, this checklist can be of benefit to centres for children's literature when assessing books produced in various cultures and societies. Further research may extend the validity of this checklist in different contexts, such as when assessing books for children of various ages and developmental stages.