Background: Avoidance of all breast-feeding by HIV infected mothers is recommended when replacement feeding is acceptable, feasible, affordable, sustainable, and safe. Whereas for women whose HIV status is unknown or negative, exclusive breastfeeding for the first six months is the single infant feeding option recommended. Objective: To assess the infant feeding practice of HIV positive mothers and its determinants. Methods: A cross sectional study with analytical component was conducted in 13 purposively selected health institutions with ART and PMTCT facilities in Addis Ababa during March, 2008. A total of 327 HIV positive mothers with their young infants visiting the respective health institutions were recruited in order of arrival, and assessed for their infant feeding practices. Results: Exclusive replacement feeding (ERF), exclusive breastfeeding (EBF) and mixed feeding (MF) were 46.8%, 30.6%, and 15.3% respectively. The predictors for choosing ERF were mode of delivery (p<0.05), household income (p<0.05) and disclosure of HIV status to spouse (p<0.01). The predictor for EBF, was mode of delivery (p<0.05) while for MF, disclosure of HIV status to spouse (p<0.05), parental infant feeding attitude (p<0.01) and infant illnesses (p<0.01) were the predictors. Furthermore, sticking to mothers' informed safer feeding options is challenged by some social factors. Conclusion: The present study delineated the predictors involved in making safer choices for infant-feeding options.To achieve success in exclusivity of feeding options, mothers' decision should be respected and pressure from the family/neighbors to introduce other food to the infant needs to be discouraged. Furthermore, the risks involved in each infant feeding option should be communicated and advocated to the mother/father during PMTCT to make informed choices. [Ethiop.