The continued occurrence of congenital syphilis is an indictment of the inadequate antenatal care services and poor quality of programmes to control sexually transmitted infections. More than 1 million infants are born with congenital syphilis each year. Despite national policies on antenatal testing and the widespread use of antenatal services, syphilis screening is still implemented only sporadically in many countries, leaving the disease undetected and untreated among many pregnant women. The weak organization of services and the costs of screening are the principal obstacles facing programmes. Decentralization of antenatal syphilis screening programmes, on-site testing and immediate treatment can reduce the number of cases of congenital syphilis. Antenatal syphilis screening and treatment programmes are as cost effective as many existing public health programmes, e.g. measles immunization. Diagnosis of congenital syphilis is problematic since more than half of all infants are asymptomatic, and signs in symptomatic infants may be subtle and nonspecific. Newer diagnostic tests such as enzyme immunoassays, polymerase chain reaction and immunoblotting have made diagnosis more sensitive and specific but are largely unavailable in the settings where they are most needed. Guidelines developed for better-resourced settings are conservative and err on the side of overtreatment. They are difficult to implement in, or inappropriate for, poorly-resourced settings because of the lack of investigative ability and the pressure on health facilities to discharge infants early. This paper offers recommendations for treating infants, including an approach based solely on maternal serological status and clinical signs of syphilis in the infant.