Vertical transmission of the dengue virus is rare and infrequently reported in the literature. We report the case of a term newborn presented with high-grade fever, generalised petechial rash and hepatomegaly at the age of 5 days, with a history of dengue fever in the mother at 3 days before delivery. The diagnosis was nearly missed because the infant’s dengue NS1 antigen test was initially negative and subsequently positive. After the convalescent phase, the infant developed a new-onset fever with lethargy and drowsiness. Dengue encephalitis was diagnosed with support from a positive dengue reverse-transcriptase PCR in the cerebrospinal fluid. This report has shown the importance of clinical awareness. Early recognition of congenital dengue and vigilant monitoring will contribute to appropriate early management and decrease neonatal morbidity and mortality.