Background: HIV and HBV are major public health problem worldwide with highly prevalentrnin developing countries like Asia and Sub-Saharan Africa. Both of these infections share similarrnmode of transmission which is horizontal and parental transmission. Community primarily basedrnstudies regarding the prevalence of every viral infection among women on comprehensivernabortion and care unit at selected sub cities in Addis Ababa Ethiopia has not been conducted. rnObjective: To determine the Magnitude of HBV and HIV among woman at comprehensivernabortion care units and their knowledge, attitude and practice at selected public health institute inrnAddis Ababa, Ethiopia from December 2019 to May 2020. rnMethods: Across sectional study was conducted among 423womenattending on comprehensivernabortion and care at private and government health care units, at Addis Ababa, Ethiopia fromrnDecember 2019 to May 2020. A structured questionnaire was used to collect data on, sociodemographicrncharacteristics,rnassociatedrnriskrnfactors,rnknowledge,rnrnattitude and practice via face tornface interview. The presence of antibodies to HIV was tested based on the national testingrnalgorithm. Hepatitis B surface antigen was tested using rapid test in adherence with thernmanufacturer instruction and positive results was confirmed by Bio-Rad ELISA kits. Data entryrnand analysis was done using SPSS. rnResults: The overall prevalence of HBV and HIV among participants was7.6% (n=32/423) andrn4.7% (n=20/423) respectively. The prevalence of HIV is higher in the age group of 20-24rnyears old with 7.8 %( n=8/103). Similarly, HBV was higher in the age group of 30-34 yearsrnold with 13.6% (n= 9/66). From the total participants, 78.6% did not know how the disease isrntransmitted, 77.8% (n=329/423) believed that HBV can be transmitted through contaminatedrnwater, 81.6(n=343(/423) had no information about the availability of HBV vaccine and 96% rn(n=406/423) were not vaccinated. rnConclusion: The magnitude of HBV and HIV among participants of the study wasrnintermediate it might be due to low knowledge, attitude and practice towards the transmissionrnand prevention of the disease. Therefore, necessary to creating awareness for woman about therntransmission and prevention mechanisms of HBV and HIV infection. Large scale study isrnrecommended at national level.