Background and Objective: Domestic violence is an important health problem all over the world. The aim of this research was to determine the prevalence of domestic violence in pregnant women and its relation to some features like family and social support and the reasons for tolerating violent relationship. Materials and Methods: This correlational prospective study was conducted on 132 pregnant women admitted to Zanjan Mother and Child Health clinics for prenatal care in 2009. A semi- structured questionnaire was filled out during a private interview to collect the data. For analyzing the collected data, chi- square, Pearson correlation coefficient, and Fisher tests were used. Results: The incidence of domestic violence was 28%. Violence was more frequent in women in the age range of 20-29 years old. 22.7% of the selected population had experienced physical violence, 28.8% sexual violence and 28% psycho- social violence. 73.7% of participants were reported with emotional and verbal violence (10.6 % severe violence). Conclusion: There was a strong relationship between fear of husband and physical (P< 0.0001), psycho- social (P= 0.002) and emotional and verbal violence (P-Value= 0.046) and also a strong relationship between violence and breaking objects (P< 0.0001), too. Men who had more than one wife (multi partners) had done more violence (P-Value= 0.007). 15.2% of the participants had informed their family about the violence many times. In severe cases, violence had happened in the presence of others (P< 0.0001). Less severe cases happened in the cases of family intervention and support (P< 0.0001).