The purpose of this study is to determine the mental models of primary school students about the concept of environment. The research group consisted of 400 students, 219 girls and 181 boys, enrolling to the 3rd and 4th grade in a primary school located in Istanbul. The students were asked to draw the environment and explain the items they draw. Students' drawings were converted into quantitative data and scored with Draw an Environment Test-Rubric. When the drawings were examined, it was found that there are 110 different items related to the concept of environment. These items include biotic elements such as humans, different kinds of animals and plants, as well as abiotic elements such as sun, cloud, rain and sea. It was seen that there are also elements of artificial environment such as houses, cars, schools, factories and roads. Mann-Whitney U Test was used in statistical comparisons to determine the difference between the total scores obtained from the drawings according to grade level and gender. While there was a significant difference between the scores of the 3rd and 4th grade students (MD[subscript 3rd grade]=189,46 n=200, MD[subscript 4th grade]=211,54 n=200, U=17792, p=0.04), no significant difference was found in the comparisons made according to the gender (MD[subscript girls]=205,92 n=219, MD[subscript boys]=193,94 n=181, U=18632,50, p=0.29). The drawings showed that the majority of the students do not see humans as a part of the environment and they have unscientific and missing mental models about the environment. [This study is presented at the 2nd International Conference on Science, Mathematics, Entrepreneurship and Technology Education.]