Dengue is a significant public health concern across tropical and subtropical regions worldwide, principally causing disease in children. Very young children are at in-creased risk of severe manifestations of dengue infection. The mechanism of dengue disease in this population is not fully understood. In this study, we present a murine model of dengue virus primary infection in suckling C57BL/6 and BALB/c mice in order to investigate disease pathogenesis. Three-day-old C57BL/6 mice intraperito-neally infected with DENV-2 NGC were more susceptible to infection than BALB/c mice, showing increased liver enzymes, extended viremia, dissemination to organs and histological alterations in liver and small intestine. Furthermore, the immune re-sponse in DENV-infected C57BL/6 mice exhibited a marked Th1 bias compared to BALB/c mice. These findings highlight the possibility of establishing an immunocom-petent mouse model of DENV-2 infection in suckling mice that reproduces certain signs of disease observed in humans and that could be used to further study age-related mechanisms of dengue pathogenesis.