The purpose of this study was to compare exploratory behaviours in children with autism and typically developing preschool children and the course of their adaptation to novelty. A series of fi ve repeated trials was conducted, during which children were allowed to freely explore the experimental room. The results revealed differences between study groups in the overall rate of exploratory activity, which was lower in children with autism. Patterns of time characteristics of exploratory activity showed both similarities and differences between the groups. In both groups, the rate of simple exploratory behaviours (i.e. looking at an object, touching the object, manipulating one object) decreased with time, while the levels of diversive exploration (i.e. touching the wall or fl oor) increased. Children with autism engaged in less complex object manipulation than their peers. Similarly, their adaptation and habituation to a novel environment proceeded in a different way in the low stimulation zone than in the high stimulation zone. In the low and medium stimulation zones, the rate of exploration decreased with time, while in the high stimulation zone it remained relatively constant. In typically developing children, habituation occurred in all stimulation zones. These results suggest the presence of some differences between the patterns of adaptation to novelty in the two groups, which emerge in a stimulation-rich environment. Due to the limitations of the study, in particular the small number of subjects, the present paper should be treated as a preliminary report.