Objective: To evaluate hepatitis B serological markers in pregnant women from various geographical sites in Kenya.Design: A cross-sectional observational study of women attending antenatal clinics.Setting: The Kenyatta National Hospital and eight hospitals from five provinces in Kenya.Subjects: All women in their third trimester of pregnancy attending the antenatal clinic over the period June 2001 to June 2002.Main outcome measures: For each pregnant woman age and gestation were documented. Hepatitis serological markers were evaluated.Results: A total of 2,241 pregnant women were enrolled. Among them 205 women (9.3%) were positive for HbsAg and from these 18 (8.8%) were found to have HbeAg. Protective antibodies (anti-HbsAg) were detected in 669 (30.2%) of the women. There were notable significant regionaldifferences for HbsAg rates.Conclusions: These results confirm the presence of high disease carrier rate and the corresponding previously reported low level of HbeAg suggesting questionable low rate of perinatal transmission but high rate of horizontal transmission