Quality of teacher-children interactions during early childhood plays a protective effect on language development, more particularly with the more vulnerable children (Dickinson, 2011). However, the quality of these interactions, especially those supporting language development, is not always optimal (Piasta et al., 2012). It is of great concern in Belgium, where there is a need to prevent, during early childhood, an educational gap that too often depends on the socio-economic status of a child’s family (Vandenbroeck, 2015). Supporting the quality of teacher-children interactions in kindergarten may be a way to preventively support language development and educational achievement. But to date, little is known about what children experience in Belgium kindergarten, regarding language development support. The objective of this study is to document the quality of teacher-children interactions, in the second year of nursery school (4-5 years old) in the French-speaking part of Belgium. Observations take place in 23 classes. The CLASS Pre-K (Classroom Assessment Scoring System®, Pianta et al., 2008) is used for measuring the quality of teacher-children interactions. Trained observers have assessed quality of interactions along three domains: Emotional Support, Classroom Organization and Instructional support including language modeling. Results have revealed a lower quality in instructional support while showing a medium-high quality in the emotional support and classroom organization. However, scores in the instructional support increase when teachers propose activities deliberately dedicated to language. A more detailed analysis of the observations in 23 classes, in relation with number of children in the classroom and type of proposed activities will be discussed. These results will be interpreted within the particular context of kindergarten in Belgium. The present study aims at enabling a more global reflection on the modalities that can better support language development in an educational context, more ...