Routine obstetric screening for all prenatal checkups is an important issue. A study was conducted to ascertain the effectiveness of an antenatal screening program for syphilis. Charts of pregnant women for a 9-year period from 1982 to 1990 at the American University of Beirut were reviewed. Demographic data and the results of screening for syphilis were collected. In a total of 23,145 patients screened (with a biological false-positive rate of 0.3%), serological evidence of Treponema pallidum infection occurred in 0.27% of patients. The outcome in infants was satisfactory in all cases where appropriate antibiotic therapy was instituted antenatally. Thus antenatal screening for syphilis in our setting is a cost-effective program.