The purpose of this study was to determine preservice science teachers’ metacognitive awareness levels and to investigate whether their metacognitive awareness levels differ in terms of gender and grade level. A total of 188 preservice science teachers participated in the study. Personal Information Form and the Metacognitive Awareness Inventory (MAI) developed by Schraw and Dennison (1994) were utilized as data collection tools in the study. The data obtained were analyzed using the PASW Statistics 18 (SPSS Inc.). According to the results, preservice science teachers’ metacognitive awareness levels were determined generally high. However, a significant gender difference favoring female preservice science teachers was found in terms of debugging sub-component. When the total and sub-component scores of MAI were examined by grade level, a significant difference was found in the sub-components apart from conditional knowledge and debugging. Suggestions were made based on the findings obtained from the study.