BackgroundrnPreventing unintended pregnancy is one of the 4 pillars of prevention of mother to childrntransmission program. Counseling and provision of contraceptives to HIV infected women whornare on ART is an important strategy to prevent unintended pregnancy and its complicationrnamong HIV positive women who wish to limit the number of their children or delay pregnancy.rnWorld Health Organization considers providing safe and effective contraceptive to HIV infectedrnwomen as one strategy for preventing pediatric infections. Despite these adopted strategies veryrnfew HIV positive women who wish to delay or limit the number of children are using modernrncontraceptive methods.rnObjective: To assess utilization of modern contraceptives by women of reproductive age whornare attending ante retroviral therapy(ART) clinic and associated factors in public health facilitiesrnin Arada sub city, Addis Ababa, Ethiopia.rnMethods: Institutional based quantitative cross-sectional study was conducted in selected 5rnpublic health facilities in Arada sub city from February to March, 2016. A systematic randomrnsampling technique was used to select study participants. Three hundred and forty eight eligiblernwomen of reproductive age who were on ART were interviewed by using a pre tested structuredrnquestionnaire to assess modern contraceptive utilization status. Data entry and cleaning wasrndone using Epi Info version 3.5.1 and then exported to SPSS version 20 using stat transferrnsoftware version 12 for analysis. Bivariate analyses were done for each independent variable andrnthe outcome variable to select variables for the multivariate analyses. Variables which showedrnp-value of less than 0.25 during bivariate analysis were entered into multivariate logisticrnregression model to identify their independent effects. Odds ratio was used to measure thernstrength of association between the dependent and independent variables while95% confidencerninterval was used to determine the significance of the association. Tables and figures were usedrnto present the results of the study.rnResult: One hundred (28.7%) of the respondents used at least one method of modernrncontraceptives to avoid or delay pregnancy. Condom was the most utilized type ofrncontraceptives. Out of one hundred contraceptive users 85.2% were using dual contraceptives.rnMarital status (currently married) (AOR 3.15, 95% CI 1.50-6.61),having open discussion withrnsexual partner about contraceptive use (AOR8.03, 95% CI 4.22 to15.28), peersâ€™ positiverninfluence (AOR 2.39,95% CI 1.09 to 5.22) and not having perception of being HIV positive affectrntheir contraceptive use (AOR 0.2, 95% CI 0.11 to 0.37) were the major determinant factorsrnidentified to modern contraceptive utilization among ART attending women.rnConclusion and recommendation: Utilization of modern contraceptives by ARTrnattending HIV positive women of reproductive age in the study sub city was low (28.7%).rnCondoms were the most frequently used contraceptive method. The proportion of women withrnHIV using dual contraceptive were high (85.2%).Being currently married, having openrndiscussion with sexual partner, peersâ€™ positive influence and not believing about the negativerninfluence of HIV on contraceptive use have positively affected contraceptive use by ARTrnattending HIV positive women in the study area. Strengthening counseling on the importance ofrncoupleâ€™s discussion as well as health education about HIV and family planning as part of ARTrncare and treatment to avoid negative perception towards contraceptive use is recommended.rnKey words: contraceptive utilization, HIV positive, modern contraceptive, family planning