The programme of the current vaccination campaign against hepatitis B in Italy considers the newborn of hepatitis B surface antigen (HBsAg) positive mothers to be high priority. Pregnant women are screened for HBsAg during the third trimester of pregnancy. All newborn of HBsAg positive women, regardless of the mother's status of hepatitis Be antigen (HBeAg), are given a single dose of hepatitis B immune globulin within 24h after birth and the first dose of hepatitis B vaccine within 7 days after birth. During the period 1984-1988 the percentage of pregnant women screened for HBsAg increased from 32% in 1984 to 71% in 1988 (P less than 0.001). The prevalence of HBsAg positive mothers was stable, ranging from 2.2% to 2.5%, but with wide regional differences (range 0.3%-6.4%). The screening compliance of pregnant women has been significantly better (P less than 0.01) in regions at a lower (less than 5%) HBsAg carrier rate. The percentage of children born to carrier mothers, who received active plus passive immunization, ranged from 75% to 85%. The number of infants immunized as percentage of those expected to be immunized (applying the observed prevalence of carrier mothers to the total number of deliveries by year) increased from 29% in 1984 to 62% in 1988 (P less than 0.01). No serious side effects were reported.