Kindergarten and primary school represent fundamental educational institutions in Croatia and in the world. However, a discrepancy can often be observed between the institution of kindergarten and the institution of school, and the divergence in educational systems can be observed most in the phenomenon of a child's transition from kindergarten to primary school. When a child leaves kindergarten and starts elementary school, his physical, psychomotor, intellectual and socio-emotional maturity should be assessed. In order for the child to be adequately prepared for the transition from kindergarten to primary school, most kindergartens run a preschool program, in which the child acquires the basic skills he needs to navigate the demanding environment of the kindergarten. There are two models that explain a child's transition from kindergarten to primary school: the child-ready-for-school model and the school-ready-for-child model. The child-ready-for-school model does not insist on sufficient communication between kindergarten and primary school, while the school-ready-for-child model is based on the cooperation of the two mentioned institutions. The influence and characteristics of a child's transition from kindergarten to school are particularly visible in the various skills that the child acquires, and some of the most important skills are communication skills and language skills, which include listening, speaking, reading and writing. It is important to insist that both kindergarten and school are linguistically adapted to the child, and that pre-reading skills, speaking skills and pre-writing skills are developed in both institutions. The conducted research has shown that educators and teachers do not have a sufficiently pronounced awareness of the importance of cooperation between kindergarten and primary school when a child transitions from one educational system to another, and this can be connected to the fact that there is not enough education on this topic in the system of higher education.