Retrieval practice is known to enhance long-term memory retention, a phenomenon termed as retrieval practice effect. Two experiments (NWhite = 202), showed that the effect was present in preschool age (5-6 years) and had a boundary condition, namely, amount of initial learning. Specifically, there was a considerable effect only when children reached a sufficient retrieval success rate during practice as a consequence of multiple initial learning cycles. Corroborating the robustness of our findings, the effect was present for both recall (d = 0.315) and recognition (d = 0.324) and did not depend on whether the forms of retrieval were the same or different during practice and final test. Important implications for early childhood education and development are discussed.