Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by symptoms that include social communication impairments, interaction deficits, and repetitive and stereotyped behaviors. Recent studies have suggested that imbalanced cytokine levels are associated with impaired behavioral outcomes in individuals with ASD. VGX-1027 is a potent immunomodulatory compound that has shown promise for the treatment of several neuroinflammatory disorders. Here, we studied the effects of VGX-1027 on BTBR T+ Itpr3tf/J (BTBR) mice, an animal model of autism. BTBR mice exhibit most of the core behavioral features of ASD, such as reduced sociability and increased repetitive behaviors. In this study, we investigated the effects of VGX-1027 on self-grooming, marble burying and sociability tests using BTBR mice. We further examined its effect on IL-1β, IL-6, IL-10, TNF-α, IFN-γ, and NF-κB p65 production in splenic CD4+ cells and on IL-1β, IL-6, IL-10, TNF-α, IFN-γ, COX-2, and iNOS (NOS2) protein and mRNA expression in brain tissues. The administration of VGX-1027 was found to attenuate self-grooming and marble burying behaviors, and enhance social interactions in BTBR mice. Additionally, VGX-1027 treatment resulted in a substantial decrease in IL-1β, IL-6, TNF-α, IFN-γ, and NF-κB p65 production, but increased IL-10 production in CD4+ T cells. Moreover, this agent was also found to significantly decrease IL-1β, IL-6, TNF-α, IFN-γ, COX-2, and NOS2 levels and increase IL-10 expression at the protein and mRNA level in brain tissues. Based on results using BTBR mice, our data provide the first evidence that VGX-1027 could potentially be used for the amelioration of autism-like symptoms.