The analysis of 8th grade students' concept definitions and concept images can provide information about their mental schema of fractals. There is limited research on students' understanding and definitions of fractals. Therefore, this study aimed to investigate the elementary students' definitions of fractals based on concept image and concept definition. The descriptive method was used in this study. The sample under investigation comprised 70 elementary school students in grade 8 from three different regions: the Black Sea, and Central Anatolia and Aegean regions in Turkey. Data were collected by an open-ended questionnaire with two parts. The first part was an examination of the students' written explanations of fractals and the second part was an analysis of the students' fractal drawings. The questionnaire was developed by the researcher based on previous studies in the areas of teaching and learning fractals. Data was categorized by semantic content analysis and analyzed using descriptive and inferential statistical methods. The findings showed that students had problems both in personal concept definitions and the formal definition of fractals. Moreover, students' fractal drawings were more successful than their formal definitions.