Background: HIV AIDS related mortality and morbidity become a challenge for the world.rnSub-Saharan Africa including Ethiopia is the most affected region and one of the reasons forrnnew HIV infection is HIV transmissions from the sero-positive partners to their sero-negativernpartners among discordant couples. Despite, high risk of HIV transmission from positivernpartner to negative partner among discordant couples, research, and follow up intervention arernminimal in Ethiopia.rnObjective: This study aimed to assess rate of HIV sero-conversion and predictors among seronegativernmalernpartnersrnlivingrnwith HIVrnpositivernwomenrnin Addis Ababa,rnEthiopia,rn2019. rnrnMethod:rnrnInstitutional based retrospective cohort supplemented by in-depth interviewrn(Convergent parallel mixed method) was used to conduct the study. All eligible two hundredrntwenty seven (227) sample medical records used for the quantitative study. Thirteenrnpurposively selected male partners were involved in the in-depth interview. Epi-data versionrn4.2 and SPSS version 25 were used for data entry and analysis, respectively. Cox regressionrnwas used to identify predictor variables. The in-depth interview analyzed thematically throughrnATLAS-ti7 software.rnResult: In this study, 227 sero-negative male partners living with HIV positive women werernfollowed for a total of 60 months and 38(16.7%) sero-conversion were observed. The overallrnsero-conversion rate in the cohort during the 7156 person-years of observation (PYO) was 6.4rnper 100 (95% CI: 0.0038639- 0.0072979) person-year follow up. Time of ART initiation, CD4rncount, condom use, and desire of pregnancy were identified significant predictor of seroconversion.rnrnSero-negative male partners living with HIV positive women experiencedrnchallenging life situations because of fertility desire, fear of HIV infection, deciding torncontinue with their relationship, lack of special support method, fear of discrimination,rnhopelessness and lose confidence.rnConclusion and recommendation: Risk of HIV transmission from positive partner to theirrnsero-negative partner was poorly controlled discordant couples. Therefore, consistent condomrnuse and early ART treatment initiation should get emphasis among discordant couples. Desirernof fertility should be considered under medical advice to minimize the risk and sero-negativernpartners should get improved counseling and support method.