The current study explored the assessment literacy of 11 secondary preservice teachers. The authors examined how the preservice teachers understood assessment tools as well as their reasons for using assessment. Furthermore, the authors investigated how the preservice teachers incorporated assessments into inquiry-based science units. Findings reveal that preservice teachers understood several ways to use assessment for learning. However, the inclusion of assessments contained within the science units did not fully align with the views of assessment the preservice teachers presented in their teaching philosophies or journals.