The experience of peer play during the juvenile phase in rats is known to be important for the development of adult social competence. Adult social competence is also compromised by damage to the orbitofrontal cortex (OFC), an area known to be involved in social behavior. We therefore hypothesized that the functioning of the OFC in social behavior is facilitated through the experience of peer play during the juvenile period. Further, because the OFC and medial prefrontal cortex (mPFC) are known to be reciprocally responsive to a variety of manipulations, we suspected that the functioning of the mPFC is also responsive to the experience of peer play during development. Female Long-Evans rats were raised in conditions that varied with respect to the experience of peer play, and Golgi techniques were used to examine the neuronal morphology of the OFC and mPFC. The results indicated that the neurons of the OFC responded to the number of peers present, not whether those peers engaged in play or not, whereas the neurons of the mPFC responded specifically to the experience of play.