Background: Completion along continuum of care for maternal and newborn health (MNH) service like antenatal care, skilled birth attendance and postnatal care services is one of the  currently recommended strategies to reduce both maternal and neonatal mortality to achieve the global target of ending preventable maternal and under five children’s mortality. Although studies on factors affecting each segment of MNH services were well documented in Ethiopia, there is a dearth of evidence on the level of continuum of care and factors associated with it. Thus, this study tries to fill this gap in the country in general and in the study area in particular.

Methods: A community- based cross sectional study was conducted among 438 postnatal women who gave births in the last one year in Arba Minch Health and Demographic Surveillance Site (HDSS). The sample women were selected by using computer generated random numbers from the list of women who gone at least six-weeks after birth. A pre-tested structured interviewer-administered questionnaire was used for data collection. Data was entered and coded in Epi-data and analyzed using SPSS software version 23. Binary logistic regression model was fitted to identify factors associated with the dependent variable.

Results: The overall completion along the continuum of care was 42(9.7%).  The factors significantly associated with continuum of care completion were early antenatal booking (before 16 weeks) [AOR: 10.751, CI (5.095, 22.688], birth preparedness and complication readiness [AOR: 2.934, CI (1.414, 6.087), pre-pregnancy contraception utilization [AOR: 3.963, CI: 1.429, 10.990], employed women [AOR: 2.586, CI: ((1.245, 5.371))], and planned pregnancy [AOR: 3.494 CI :( 1.068, 11.425)].

Conclusion: Completion along continuum of care was low in the study area. Thus, efforts in improving completion of the cares should focus on early booking during antenatal period, reducing unplanned pregnancy, and improvement on birth preparedness and complication readiness interventions.