Screening for congenital hypothyroidism (CH) among the Arab population of the West Bank began in May 1987 as part of the neonatal screening program in Israel. In the West Bank many infants are born at home or are released from the hospital on the 1st day after birth and thus cannot be screened. However, we tried to reach the infants before the age of 1 month at the maternal and child health centers, where they receive immunization. In this screening program, 64% of the infants were sampled by the 1st week and 93% by 3 weeks of life. In contrast to the screening in Israel, where thyroxine determination is followed by thyroid-stimulating hormone measurement, in the West Bank thyroid-stimulating hormone was tested first in order to decrease the recall rates. From June 1990 to February 1994, 49,694 infants were screened in the West Bank, of whom 24 with CH were detected (an incidence of 1:2,070). From January 1987 to February 1994, 28,938 infants were screened in East Jerusalem, of whom 20 with CH were detected (incidence 1:1,447). There were differences between the incidence rates in the various districts. The incidence rates were higher than those reported from industrialized countries, but similar to those found in Saudi Arabia. This may be due to the high degree of consanguineous marriages among Arab populations and to environmental factors. In conclusion, in spite of the many difficulties, both practical and political, CH screening in the West Bank is feasible. Although screening all newborns shortly after birth is not possible, this study shows that a high percentage of them can be screened at a time when they can still be effectively treated. Our results could be used in due time as a baseline for a future independent screening program.