Cognitive activation is one of the central quality characteristics of teaching. Studies which analyzed cognitive activation in science instruction and its influence on the achievement and the interest of students, took most of the times place in higher grades. Since scientific thinking can be taught at a very early stage and, in particular, experimental situations should be designed cognitively activating so that they can be optimally used as learning opportunities. Therefore, this study examined cognitive activation in experimental situations. For this purpose, we video recorded five lessons in primary schools as well as five lessons in kindergartens in Germany. The results showed that in the investigated experimental situations, only a few cognitively activating measures were implemented by the kindergarten educators and the primary school teachers. It is noticeable that the category Challenging questions was used most frequently while the category Instructional dialogue was by far the rarest in the videos.