This study examined the extent that inhibition among familiar peers was related to inhibition among unfamiliar peers versus exclusion by familiar peers at 2?years of age. Peer inhibition at 2?years of age was assessed by both mothers and teachers on versions of the Behavioral Inhibition Questionnaire and the Preschool Play Behavior Scale (N?=?141 children, 53% girls) that were adapted such that each item was posed separately regarding familiar versus unfamiliar peers. A subset of participants (n?=?82) were also observed during free-play with familiar childcare classmates at 30?months using the Peer Interaction Observation System-Early Childhood. There was no significant relation between children exhibiting extreme levels of inhibition with familiar versus unfamiliar peers across informants. Substantial numbers of children demonstrated inhibition with familiar but not unfamiliar peers (18%), with unfamiliar but not familiar peers (10%), or with neither familiar nor familiar peers (69%). In contrast, few children exhibited inhibition with both familiar and unfamiliar peers (3%). Observed peer exclusion among familiar childcare peers was systematically positively correlated with the display of inhibition among familiar childcare peers but not unfamiliar peers across informants. These findings suggest that proximal relational learning processes may have more impact than inhibited temperament on inhibition among familiar peers at 2?years of age. However, the concurrent correlational nature of this study does not provide evidence about the direction of effect. Additionally, in the future, it will be important to conduct observations of children's interactions with both familiar and unfamiliar peers.