In the study of population not only is the size important but also the rate of growthrnand the dynamics of its change. This is more so in developing countries with their highrnpopulation growth rate and the much higher urban and primate city growth. AddisrnAbaba has been reported to be growing at around 5 per cent per year and the facilities,rnamenities, infrastructures, etc. have not been able to accommodate this growth.rnPlanners and policy makers have been concerned about this and demographers haverna role to play in distinguishing the factors behind this high growth.rnUsing a multi-stage stratified sampling procedure a total of 1000 households werernselected from 50 Kebeles in Addis Ababa and a total of 1133 respondents wererninterviewed for the present study. In each of the households selected into the sample,rneach eligible respondent (both migrant and non-migrant ever married women aged 15-rn49) was asked a range of questions covering her marital, pre and post migration historyrnas well as on related socio-economic status history.rnThe analysis indicated that, at macro level there is not much difference in thernfertility performance of migrants and non-migrants in Addis Ababa. This patternrncontinued even when we categorized them into different socio-economic andrndemographic variables; like economic activity status, ethnicity, education, age at firstrnmarriage, breastfeeding durations and contraceptive useThe micro level analysis attempted to identify the specific mechanisms throughrnwhich the said socio-economic variables affected fertility, by controlling for age atrnmarriage, breastfeeding duration and contraceptive use. Whereas the migrant - nonmigrantrndifferential was virtually not in the expected direction, controlling for thernproximate determinants, the higher migrant than non-migrant fertility was observed.rnAmong the former, fertility was apparently higher among those of rural origin thanrntheir urban counterparts. In the area of mortality also, we observed that, migrationrntends to affect positively the survival of the children of migrants.