In the present study, primary school students' and pre-service teachers' ideas' comparison of Seasons, are investigated. The research was carried out in 9 primary schools of Athens with a sample of 142 5th grade students and in the Pedagogical department of the University of Athens, also with a sample of 142 pre-service teachers. Written reports were used for gathering scientific data while students had also the opportunity to support their answers with drawings. The results showed: that pre-service teachers address, notions which involve the Sun and Earth moving their position, while primary school students also address a) human centered notions b) tautologies and c) notions which involve near and familiar objects. Both populations of the sample adopt mainly two schemes of explanations: a) periodic variations in the distance between the Sun and the Earth and b) periodic alterations in the Earth-Sun relative orientation.