en General پژوهشي Research Article Background and Aim: Sexual transmission is one of the routes of hepatitis B transmission. This study aimed at assessing the prevalence of hepatitis B among the spouses of patients with hepatitis B. Methods: This cross-sectional descriptive-analytical study was done on 397 spouses of chronic carriers of hepatitis B, who had referred during years 2003 to 2014 to a private clinic of infectious diseases in Birjand, Iran. Serological tests for hepatitis B surface antigen and anti-core antigen antibody were performed for all participants. Data were entered in the SPSS software (v. 19.0) and analyzed through the Chi-square and Fisher&rsquo;s exact tests at a significance level of less than 0.05. Results: The prevalence of hepatitis B among participants was 8.3%. Resolved hepatitis B was observed in 40.6% of the participants. The prevalence of hepatitis B surface antigen positivity and hepatitis B core antigen antibody positivity among participants whose spouses had shown hepatitis B e-antigen positivity was 15.8% and 70.2%, respectively. This rate among participants whose spouses had shown hepatitis B e-antigen negativity was 7% and 36.3%, respectively. Hepatitis B e-antigen positivity among participants&rsquo; spouses was significantly correlated with transmission of hepatitis B core antigen antibody positivity (odds ratio = 4.18; 95% confidence interval: 2.08 - 8.38; P < 0.001). Conclusions: This study suggests the high risk of hepatitis B interspousal transmission, particularly among patients with hepatitis B e-antigen positivity. Therefore, public education about hepatitis B and emergency vaccination against it are essential for spouses of infected patients, to prevent interspousal transmission. Epidemiology,Hepatitis B,Interspousal Transmission 0 0 http://mcj.bums.ac.ir/browse.php?a_code=A-10-1-63&slc_lang=en&sid=1 Ghodsiyeh Azarkar 10031947532846003561 10031947532846003561 No Birjand Infectious Disease Research Center, Birjand University of Medical Sciences, Birjand, IR Iran Masood Ziaee 10031947532846003562 10031947532846003562 Yes Masood Ziaee, Birjand Infectious Disease Research Center, Birjand University of Medical Sciences, Birjand, IR Iran. Tel: +98-9151613942, E-mail: dr.m.ziaee@gmail.com Bita Bijari 10031947532846003563 10031947532846003563 No Birjand Infectious Disease Research Center, Birjand University of Medical Sciences, Birjand, IR Iran Mahmood Hosseini 10031947532846003564 10031947532846003564 No Allied Medicine School, Birjand University of Medical Sciences, Birjand, IR Iran