Background: Immunization program has become the most effective public health measure for the controlling of vaccine-preventable disease among children. Globally, immunization coverage is increasing, however, 19.4 million infants not vaccinated in 2015. Ethiopia is one of the Sub-Saharan African countries with a high number of children unimmunized. Although there are studies about immunization among children, there is a dearth of information about factors associated with full immunization. Therefore, this analysis was performed to identify factors associated with full immunization among children aged 12-23 months in Ethiopia. Methods : The analysis was done based on the 2016 Ethiopian Demography and Health Survey data. The 2016 Ethiopian Demography and Health Survey was a community based, cross-sectional study conducted from January 18, 2016, to June 27, 2016. The survey used a two-stage stratified random sampling technique. A total of 2004 children aged 12-23 months were included in the analysis. Both descriptive and logistic regression analyses were performed using STATA. A P-value less than or equal to 0.05 at 95% confidence interval was set to test statistical significance. Result: Fully immunization coverage among children was 38.6%. Born at a health facility, living in Dire Dewa city, source of information from the card, mothers’ educational level (primary and secondary plus), and marital status (married and formerly married) were found positively associated with full immunization. On the other hand, smoking history of mothers and living in Afar, Amhara, Somalia, Gambella, and Oromia regions were negatively associated with full immunization. Conclusion: Fully immunization coverage among children was low. Children who were born at a health facility, source of information from the card, living Dire Dewa city, and whose mothers’ literate and married had higher Odds of being fully immunized. On the other hand, children whose mothers’ had a history of smoking and living Afar, Somalia, Gambella, Amhara and Oromia regions were had lower Odds of being fully immunized. Therefore strengthening institutional delivery and keeping immunization cards should be strengthened, and more emphasis should be given to children whose mothers’ illiterate, never married, smoker and living in Afar, Amhara, Somali, Gambella, and Oromia regions.