In the present study the possibility of teaching basic ideas of chaos theory to pre-service teachers is investigated. Based on a commercial chaotic pendulum interconnected with a data acquisition interface, a teaching and learning sequence is developed. 18 pre-service teachers of primary education took part in the investigation. To collect the data, the teaching experiment method is used. The analysis of the data show that most of the students recognize firstly, the existence of deterministic laws in random-like motion, secondly, the possibility of having deterministic laws without having long-term prediction and finally that little deviations could cause enormous differences in the outcome of deterministic processes.