The neuropeptide arginine-vasopressin (AVP) has long been implicated in the regulation of social behavior and communication, but the sources of AVP release relevant for behavior have not been precisely determined. Ablations of the sexually dimorphic AVP cells within the bed nucleus of the stria terminalis (BNST), which are more numerous in males, affect social behavior differently in males and females. However, it is unknown whether these behavioral effects are caused by a reduction of AVP or of other factors associated with these cells. To test the role of AVP specifically, we used an shRNA viral construct to knock down AVP gene expression within the BNST of wild-type male and female mice, using scrambled sequence virus as a control, and evaluated subsequent changes in social behaviors (social investigation, ultrasonic vocalization (USV), scent marking, copulation, and aggression), or anxiety-like behaviors (elevated plus maze). We observed that, in males, knockdown of AVP expression in the BNST strongly reduced investigation of novel males, aggressive signaling towards other males (tail rattling, USV), and copulatory behavior, but did not alter attack initiation, other measures of social communication, or anxiety-like behaviors. In females, however, BNST AVP knockdown did not alter any of these behaviors. These results point to differential involvement of AVP derived from the BNST in social behavior.