Congenital syphilis is the infection by Treponema pallidum of the newborn, due to mother-to-child transmission of spirochaetes during pregnancy. It remains as a major cause of preventable fetal and neonatal morbidity and mortality if the mother is not opportunely treated. This highlights the importance of an adequate prenatal control, early screening for maternal infection and timely treatment. Although Chile has experienced an increase in the incidence of syphilis in the general population, a stable rate of congenital syphilis in 0.1/1.000 live births has been maintained. In this case report, we present a newborn whose mother did not have antenatal control and showed dermatological lesions compatible with syphilitic pemphigus.