Arginine vasopressin (AVP) is a neurohypophyseal peptide best known as an antidiuretic hormone. AVP receptors have been classified into three subtypes: V1a, V1b, and V2 receptors. The V1a receptor (V1aR) and V1b receptor (V1bR) are widely distributed in the central nervous system, including the cortex and hippocampus. In the present study, we examined the performance of V1aR or V1bR knockout (KO) mice compared to wild-type (WT) mice in behavioral tests. V1aR KO mice exhibited impairments of spatial learning (eight-arm radial maze), prepulse inhibition (PPI) and social behavior in comparison to WT mice. On the other hand, V1bR KO mice also displayed impairments of PPI and social behavior. These results suggest that V1aR and V1bR may be involved in psychiatric disorders associated with impairments of sensorimotor gating and social behavior such as schizophrenia and autism.