Background: Hepatitis B virus (HBV) is a highly contagious virus which is 50-100 times morerninfectious than HIV but have similar mode of transmission. Chronic HBV infection remains arnmajor health threat. The prevalence of HBV infection among an antenatal population may be arnreliable indicator of HBV prevalence rate in the general population. However, the knowledge,rnattitude, practice and the prevalence of HBV infection among pregnant women are not studiedrnwell in developing countries like Ethiopia.rnObjective: To assess the magnitude of Hepatitis B surface antigen and level of knowledge,rnattitude practices related to Hepatitis B infection among pregnant women attending three HealthrnCenters in Addis Ababa, Ethiopia.rnMethod: A cross sectional study was conducted from March to May 2014 among pregnantrnwomen attending selected Health Centers in Addis Ababa, Ethiopia. A total of 260 pregnantrnwomen were included in the study. Volunteer participants were asked to complete arnquestionnaire, and offered testing for HBsAg infection. The Health Centers were selected basedrnon convenience sampling technique. The data was analyzed using SPSS version 16 software. Chirnsquare test and odds ratios were used to determine association between dependent andrnindependent variables. Levels of statistical significance were determined at P value < 0.05.rnResult: Of the total of 254 screened pregnant women, 4.7% were positive for HBsAg. Thernhighest prevalence (8.7%) was observed among 30-34 age groups, among self employed (6.7%),rnin those with primary education (7.6%), and those having three children (6.5%). However, therernwas no statistically significant association between the prevalence of HBsAg and sociorndemographic characteristics P > 0.05.rnOut of 254 participants, 138(60.8%) were related the poor knowledge range. Poor knowledgernwere seen apparent in responses to questions relating to, 28.7% they have heard of a diseaserntermed as hepatitis B, only 18.9 believed that HBV is viral disease, 12.2% know symptom of thernHepatitis B and 18.9% that transmission can occur from mother to child during pregnancy.rnEducated participant had more knowledge about the HBV and were reduce risk of HBV infected.rn[AOR=0.13; 95%CI, 0.04-0.52, P=0.004] and those with better knowledge were three timesrnmore likely to be tested for HBV [AOR=2.83; 95%CI, 1.3-6.1 P= 0.00]. Majority of thernrespondents 214 (84.3%) believe that they can never get infected with HBV, 11.8% stated thatrnthey will go to traditional healer to get treated for HB. 125 (49.2%) agreed to consult a physicianrnas their first choice of treatment as a good attitude towards the virus. The overall negativernpractice were 57.3%, 219 (86.2%) never had HBV screening and 248 (97.6%) stated a negativernimmunized status against HB and 239(94.1%) have never attended any health educationalrnprogram on HB. But, 198 (79.0%) participants agreed that they will go for further investigationrnand treatment if they are infected with HB.rnConclusion: The prevalence rate of HBsAg was 4.7%. The overall good knowledge of thernparticipants was 39.2%, low responses were seen attitude related questions and good practicernwas 42.7%. Although Hepatitis is recognized to be one of the major health problems, thesernfindings indicate a lack of understanding about control and the prevention of HB. Therefore,rnpublic health measures must include regular health education.rnKey Words: HBsAg, Seroprevalence, KAP, Pregnant women.