Previous studies done in Ethiopia indicated that the main factors affecting to incomplete immunization are multiple such as age of the mother, parents education, knowledge about immunization, ANC) and PNC, marital status, mother’s occupation, child sex, place of birth, birth order, residence and distance to health intuitions. Even though there is a agreement about the above problems to the contribution of incomplete vaccination, the problem still endured with much little enhancement posing a challenge to the country health care delivery system(11, 20, 21). For that reason studying the determinants of incomplete immunization allows for effective implementation of policy where there is a high rate of defaulter.
Despite few local studies conducted in different parts of the country, no adequate study tried to identify predictors of incomplete vaccination among children 12-23 months of age in Semen Bench district, Bench Majii zone, Southwest, Ethiopia. Hence, there is a need to carry out a research to assess the determinants of incomplete childhood vaccination and to generate data that could be used for better planning and strengthen of vaccination service.