Background: Unplanned pregnancy is a pregnancy which is reported to have either unwantedrn(the pregnancy occurred when no children, or no more children were desired) or mistimedrn(the pregnancy occurred earlier than desired). Itis a public health concern; globally itrnaccounts 40% of all pregnancies. Every year, around 1.9 million Ethiopian women have anrnunplanned pregnancy.rnObjective:Thus, the general objective of this study is to examine the prevalence of unplannedrnpregnancy and its associated factors in Addis Ababa, at selected health centres. In line withrnthis, the study specifically tries to assess the prevalence of unplanned pregnancy, examine thernassociation between unplanned pregnancy and the associated factors.rnMethodology:An institutional based cross-sectionalstudywasused.To do so, 397 questionnairesrnwere distributed to sampled populations after determining the sample size. The sample sizernwas allocated proportionally to the selected health centres based on average number ofrnpregnant following antenatal care. All pregnant women in antenatal care clinic who metrninclusion criteria were recruited for the study. And the collection rate of the questionnairernwas 100 percent. Data were analysed using SPSS version 25. Bivariate analysis andrnmultivariate logistic regressions were carried out to determine the effect of independentrnfactors on unplanned pregnancy.rnResults: The prevalence of unplanned pregnancy is 28.7 % per total number of pregnant whornfollows antenatal care clinic of Addis Ababa city selected public health institutions. Thernmajor findings of this study showed that the magnitude of unplanned pregnancy was high.rnMarital status, age at first pregnancy, occupation, life time number of partners and ever userncontraceptiveswas statistically associated with an unplanned pregnancy. There is seemingrnnecessity to plan strategies of communication within couples or individuals on reproductivernhealth especially on fertility and promote family planning methods.