HIV\AIDS was recognized as a disease of inequality and marginalization. Women are becoming more vulnerable to HIV infection than men. Africa leads the HIV infection at a forefront and nearly 60% of people living with HIV were women of child bearing age at the end of the year 2001. AIDS virus, also, appears to be increasingly infecting married women in developing countries A total of 1276 married women aged 15 to 49 were selected in Nazareth town, the capital city of Eastern Shoa zone, using multi stage sampling method. The study aimed at assessing vulnerability of married women to HIV infections and their risk-awareness level measured by reported history of STDs or high-risk sexual behaviors by married couples and worry to have been infected by HIV respectively, using a structured questionnaire. The study also attempted to assess socio-economic factors contributing to vulnerability to HIV Results showed significant proportion of married women (26.8%) to have been vulnerable to HIV infection as measured by either of the reported prevalence of STIs in married women, which was 16.8% or prevalence of extra marital sexual relationship in either of the couples which was 2.3% and 9.3% in married women and married men respectively. Also, of the 26.8% of married women who were vulnerable to HIV infection, more than two third (66.1%) did not know they were at risk. Women who depend economically on their husband and also whose marriage decision to have been motivated for the reason of financial security are found to be more vulnerable to HIV infection. Significant proportion of such women was also found to be not aware of their being at risk. In conclusion, significant proportion of married women were vulnerable to HIV infection and, the majority of married women who were vulnerable did not know they were at risk of acquiring HIV. Vulnerability is more in women who were economically dependent on their husband. Hence, there is a need in to empower women economically by creating job opportunity and also need of awareness creation on safe sex practices in married life and need on a skill of sexual negotiation especially by targeting married women and engaging married men as well.