The benefi ts of breast-feeding for the health of the infant, as an inexpensive and appropriaternsource of nutrients, for its simulation of a strong relationship between the mother and thernchild, and as a major source of protection against pregnancy through suppression of ovulationrnhave been very well documented. But, only few have attempted to examine the factors thatrndetermine the duration of brca s t-fcc~ i ng in Ethiopia. Thus using the appropriate stati sticalrnmodel thi s study analyzes the socio-demographic factors that determine the duration ofbrcaslfeedingrnin Urban Addis Ababa.rnData on breast-feeding from the 1995 Fertility Survey of Urban Addis Ababa carried out byrnthe Central Stati sti cal Authori ty is used for the analysis. The breast-feeding duration of thern31.78% of the mothers is found censored. Therefore, for the overall examination of the factorsrnthe Cox-regression model is used.rnThe prevalence and the med ian duration ofhreast-feeding using the Kaplan-Meier method arernestimated to be 95% and 14 months, respect ively. The log-rank test is used to examine thernbreast-feeding differentials. To know the joint e ffect of the factors and to identify the morernimportant factors a multivariate analysis is undertaken. An approach based on statisticalrnmodelling without prioritizing the variables, the ' Hierarchic' method is employed.rnThe final Cox's regression model shows that educational level of the mother is the variablernwhich signi ficantly affects the duration of breast-feeding. It is this variable with a negativernassociat ion that best detennincs the breast-feeding durat ion. The shortest duration is observedrnfor mothers with higher levels of education. Finally, re levant discussion is made and the focusrngroup to which effective breast-feeding promotion campaign should be targeted isrnrecommended.