Behavioral mimicry is the nonconscious copying of an interaction partner’s behavior and is affected by social dynamics. Whereas it has been studied extensively in adults, little is known about the development of mimicry. The aims of this study were twofold, first to identify whether young children demonstrate mimicry and, second, to investigate whether young children’s mimicry displays sensitivity to social dynamics. Using a video-based paradigm, 40-month-old children observed six types of behaviors (i.e. yawning, laughing, frowning, cheek-scratching, mouth-rubbing and head-wiggling) performed by a model which they had previously seen either helping or hindering another model. Results indicate that children carried out five of the six behaviors more often while watching the behavior videos than during baseline. However, no differences were found between the two social manipulations. We conclude that young children demonstrate mimicry like that reported in adults and discuss the possible causes of the absence of a social effect.