The goal of the current study was to compare two forms of dynamic assessment and standard assessment of preschool children's phonological awareness. The first form of dynamic assessment was a form of scaffolding in which item formats were modified in response to an error so as to make the task easier or more explicit. The second form of dynamic assessment was direct instruction of the phonological awareness tasks. The results indicate that preschool children's phonological awareness can be assessed using standard assessment procedures, provided the items require processing units larger than the individual phoneme. No advantage was found in reliability or validity for either dynamic assessment condition relative to the standard assessment condition. Dynamic assessment does not appear to improve reliability or validity of phonological awareness assessments when preschool children are given tasks that they can perform using standard administration procedures. (Contains 4 tables.)