In this paper, it is aimed to investigate the persistence of misconceptions in the topic of the human blood circulatory system among students in different grade levels. For this reason, after discussions with biology educators, two tests consisting of open-ended questions were developed by the researcher and administered to students in four different grade levels. The first test was administered to 319 5th and 7th grade students in elementary school and the second one was administered to 400 1st and 4th year university students studying in the departments of elementary school teaching, science education and biology education. Data were analyzed using qualitative methods and a number of misconceptions were detected in different grade levels. According to the results of the study, the distributions of the percentages of students’ misconceptions demonstrate a decreasing trend from elementary school students to university students without totally disappearing. The reason of this situation might be the persistence of misconceptions that are difficult to overcome. Due to their functionality, students continue to possess certain misconceptions. Hence, this characteristic of misconceptions should be considered while planning teaching activities in teacher education programs.