Developmental changes in learning from peers and adults during the second year of life were assessed using an imitation paradigm. Independent groups of 15- and 24-month-old infants watched a prerecorded video of an unfamiliar child or adult model demonstrating a series of actions with objects. When learning was assessed immediately, 15-month-old infants imitated the target actions from the adult, but not the peer whereas 24-month-old infants imitated the target actions from both models. When infants' retention was assessed after a 10-min delay, only 24-month-old infants who had observed the peer model exhibited imitation. Across both ages, there was a significant positive correlation between the number of actions imitated from the peer and the length of regular peer exposure reported by caregivers. Length of peer exposure was not related to imitation from the adult model. Taken together, these findings indicate that a peer-model advantage develops as a function of age and experience during the second year of life.