Congenital and gestational syphilis are increasingly prevalent multisystemic infections in Brazil. This study aimed to present a case series of three children diagnosed with congenital syphilis even though their mother had unreactive treponemal tests. The VDRL (Venereal Disease Research Laboratory) titers of a 22-year-old mother with three pregnancies decreased after treatment. The mother did not have a reactive treponemal test, but all the three children were diagnosed with early congenital syphilis. This case series highlights the difficulty in diagnosing gestational and congenital syphilis in Brazil.