This study aimed to determine comprehension levels of prospective teachers related to the heat and temperature concepts by using concept cartoon. Qualitative research method was used and 25 prospective teachers were included in the study. Concept cartoon in form of worksheet was used as a data collection tool. The concept cartoon distributed to prospective teachers and they were given 20-25 minutes and their answers and explanations about whether or not they agree with the statements in the cartoon were collected in writing. Obtained data were analyzed by using content analysis. Following the analyses, the prospective teachers' comprehension levels related to the concepts and the alternative concepts they had formed were revealed and the issue was discussed.