Introduction: Hepatitis is a serious danger to heath of delivery room s personnels since direct exposure to the blood occurs in 25 percents of viginal labours.

Materials and Methods:This descriptive study carried out in order to evaluate knowledge about hepatitis B among midwives and midwifery’s students in delivery rooms in hospitals related to Medical Sciences universities in Tehran. The study group consisted of 120 persons (60 midwives and 60 midwifery’s students) and hospitals were selected through cluster sampling and samples selected randomly. Data collected by a questionnaire from June to September 2002. Data were analyzed with descriptive statistics and chi-square test.

Results: Results showed that knowledge were moderate in majority of midwives and midwifery s students. There was no significant difference between knowledge about hepatitis B in three universities.

Conclusion: This research showed that knowledge of midwives and midwifery s students about hepatitis B wasn t adequate hence training courses is recommended in order to increase knowledge of midwives and more attention must be paid to education of midwifery’s students about blood born diseases, especially hepatitis B.