Concepts are defined as names given to ideas, events or objects that make it easier for us to understand the world in which we live. We must not have misconceptions to understand the world in which we live and to explain correctly the events we encounter. Considering that one of the reasons for the misconceptions students have is the teachers, the importance of identifying the misconceptions of the pre-service teachers cannot be denied. In the present study, it was aimed to determine the misconceptions of pre-service science teachers about gas pressure by Prediction-Observation -Explanation (POE) method . Twenty-six pre-service science teachers participated in the study. The data of the study, in which descriptive survey method was used, was collected by the worksheets prepared by the researchers. Collected data were evaluated by content analysis. According to the findings, it was determined that the misconceptions most frequently expressed by pre-service teachers were as “concept of gas volume, flowing of heat and air from cold to hot, closed environments are not affected by external environment changes, and pressure was not effective in gas transitions between two closed systems.” Inthelight of thefindings, it wassuggestedtopreparetext boks thatassociatescontentwithdaily life andrequirestheuse of knowledge in differentsituations. Inaddition, it wassuggestedthatteachersshouldusethequestionsevaluating how studentsunderstandtheconceptsandtherelationsamongconcepts.It is thoughtthatcarryingoutthelessonsaccordingtotheconstructivistapproachsuch as POE methodthatgivesstudents a chanceto be activewouldcontributetopreventandeliminatemisconceptions.