The purpose of this study is to explore students' understanding levels and misconceptions regarding atmosphere. The concept for the study were chosen from the Geography National Curriculum. In this study, a questionnaire was developed after a pilot study with an aim to ascertain the students' understanding levels of atmosphere. The questions in the questionnaire were in the forms of short-answer, open-ended. The questionnaire was applied to 100 students who were selected on the random basis. The students were at the 9(th) grade, and their age group was between 14-15. The sample was chosen from high schools in the city of Trabzon. At the end of study, it has been revealed that the students did not understand conception of atmosphere sufficiently, and they have lots of misconceptions about atmosphere. In the study, since it has not been seen success both in teaching and in learning of this concept, some recommendations were provided to both curriculum development experts and to teachers in teaching these conceptions. (C) 2010 Published by Elsevier Ltd.