Background: Postnatal period is defined as the first six weeks after birth and is critical to thernhealth and survival of both a mother and newborn. Most maternal and infant deaths occur duringrnthis time. Yet, this is the most neglected period for the provision of quality care. More than half arnmillion women die every year worldwide from complications in pregnancy and childbirth; mostrnof these deaths are happening during the postnatal period. Despite the fact that Post Natal Carern(PNC) service utilization would avert the death of mothers and their new born; the PNC servicernutilization is generally believed to be low in Ethiopia. Therefore, this study designed to identifyrnthe prevalence and associated factors of postnatal care service utilization.rnObjective: The main objective of the study was the prevalence and associated factors of postnatalrncare utilization inAddis Ababa 2015.rnMethods: An Institution based cross-sectional study was conducted from April 20 to May 20,rn2015 at ten randomly selected government health centers in Addis Ababa. A total of 422 Womenrnwho delivered a baby 10 weeks before the survey and who come for child immunization up torn14th weeks of delivery were included in the study. Data was collected through face to facerninterview using a preâ€“tested Amharic questionnaire. Data was entered cleaned and analyzedrnusing SPSS version 20. Frequency distributions, measures of central tendency and logisticrnregression were calculated and interpreted accordingly.rnResult:A total of 422 participants were included in the analysis which was a the response ratern98.3 %. The mean age of the participants was 26.7 %( +SD=4.4 years). The prevalence os thisrnfinding was277(65.6%) having utilization ofpostnatal care service. PNC counseling and provisionrnof appointment, counseling on danger sign, past experience of PNC utilization, and less than 6rnhours stay at health institution before discharge were showed statistical significant association forrnthe current PNC service Utilization [(AOR=32.6, 95% CI (14.7-72.3)], [ AOR (1.95, 95% CIrn(1.05-3.64)], [AOR=2.8, 95% CI (1.36-5.8)], [AOR= 0.22, 95% CI (0.06-0.83)] respectively.rnConclusion and recommendations: The overall prevalence of PNC service utilization in thisrnstudy was relatively good as compared to the HSDP IV report for Addis Ababa in thern2006Ethiopian feasibility year. To enhance PNC service utilization all women should berncounseled about the danger signs of postnatal period and provided appointment. Further allrndelivering mothers should be stayed at least for 24 hours following delivery.rnKey words: postnatal care utilization, prevalence, Addis Abab