Background: The burden of HIV/AIDS is high in Sub-Saharan countries whichrnconstitutes two third of the globe and is worst in Ethiopia. As a strategy for prevention,rncondom use practice among others remains the most effective method against HIVrninfection. Therefore identifying determinants of consistent condom use in HIV patientsrnwho were on ART had paramount importance in the prevention and control of the disease.rnObjective: To assess the sexual behavior and determinants of condom use in HIV/AIDSrnpatients who are on ART based on theory of planned behavior constructs.rnMethods: a cross sectional study design was conducted in North Showa Health facilitiesrnfrom March to April 2011. Structured questionnaire was prepared and also adopted fromrnthe theory of planned behavior and the data was collected from 337 randomly selectedrnstudy participants in North Showa ART rendering health facilities. Analysis was donernusing Cronbachâ€™s alpha reliability test, binary logistic regression, Partial correlation, andrnlinear regressions in order to know the predictors of consistent condom use and orrnintention to consistent condom use.rnResults: All the respondents filled the Questionnaires and 56% of the respondents werernfemales with the median age of 32.00+9.66 years. Among the respondents 144(42.70%) ofrnthem had multiple partners and 209(62.00%) used condom consistently and casual types ofrnpartner for those who had multiple sexual partner was the largest proportion (47.70%).rnOver half of the respondents (52.30%) had had sex without condom use with partner ofrnUnknown HIV sero-status. All components of the theory, attitude (r=0.31: p