Covert face recognition was examined in 12 young preschoolers (age range 26–48 months) by comparing their autonomic functions to slides depicting former playmates from a family nursery school that the preschoolers had attended earlier with slides of their present playmates and unfamiliar children. While all preschoolers reported corroborated overt recognition of present playmates after the experiment, only three of them did so in relation to former playmates. The distribution of yes–no responses on the overt recognition task to former playmates was not significantly different from the responses to unfamiliar children. Nevertheless, the preschoolers evidenced increased skin conductance responses (SCRs) and more pronounced heart rate (HR) deceleration to the slides depicting former classmates compared to unfamiliar children. Thus, although the preschoolers' verbal responses did not differentiate between former playmates and unfamiliar children, their autonomic functions did. These findings suggest that young children can retain memories of past experiences in an implicit form without corroborated overt recognition. Copyright © 2004 John Wiley & Sons, Ltd.