Phonemic awareness has been consistently identified as an essential skill for as well as an important predictor of later reading achievement. Children who lack these early literacy skills at kindergarten entry are more likely to demonstrate both short- and long-term reading difficulties. Despite the importance of providing intervention early, there is a paucity of research on Tier 3 early literacy interventions in preschool. A single-case multiple baseline across subjects design was used to examine the effects of a Tier 3 phonemic awareness intervention with preschool children who were identified as needing Tier 3 support in early literacy skills. The intervention was conducted individually with children, 5 to 10 min a day over an 8-week period. The results show gains in phonemic awareness for all children; however, the intervention was clearly more effective for some students than others. Factors that may have affected children’s learning are discussed.