The role of the prelimbic part (PL) of the prefrontal cortex in encoding information about conspecifics remains poorly understood. Here we explore the functional role of various neuronal classes in the PL, including pyramidal cells (Pyr), parvalbumin- (PV+), somatostatin- (Sst+), and vasoactive intestinal peptide- (VIP+) expressing interneurons, in processing information about familiar and novel social stimuli.We employed chemo/optogenetics alongside automated behavioral testing in Eco-HAB®, an RFID-based system for ecologically relevant assessment of social behavior in group-housed mice. This system allows continuous, individualized measurement of voluntary behavior, combined with the manipulation of the activity of specific neuronal populations in the PL. We evaluated animals’ responses toward known conspecifics, as well as their interest in novel social stimuli. Additionally, we conducted pilot two-photon imaging of social odors-evoked activity of excitatory and inhibitory cells in PL in behaving mice.We show that PL-constrained inhibition of Pyr, as well as activation of PV+ interneurons diminishes sociability by reducing time voluntarily spent with familiar mice. Interestingly, Pyr inhibition also leads to the heightened interest in novel social stimuli, a behavior absent in animals with activated PV+. Furthermore, activation of VIP+ cells mirrors the functional role of PV+, however, is far less pronounced. On the other hand, Sst+ activation indiscriminately disrupts interest both familiar and novel social stimuli. These findings highlight diverse role of microcuircuits in the PL for processing familiar and novel social information. Importantly, the study underscores the pivotal role of the PV+ neurons in selective encoding of familiarity.