Despite many calls, there is little research addressing teachers' knowledge of reading assessments and how they utilize assessments for reading instruction. Therefore, the current research developed and validated a reliable measure of teachers' perceptions and knowledge of reading assessments, called the "Perceptions and Knowledge of Assessment in Literacy Survey" (PKALS). Through the analysis of two separate administrations, we provide evidence for validity of the PKALS and examine the associations between teachers' characteristics and their performance on the PKALS. This research also found that teacher experience was correlated with higher knowledge; however, teachers' certification and graduate degree status were not. The PKALS can support future researchers and teacher preparation programs to identify gaps in teacher knowledge, allowing for interventions to promote student reading success.