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, antenatal care (ANC) and postnatal care (PNC), marital status, mother’s occupation, sex of the child, birth place, birth order, place of residence and distance to health intuitions. Even though there is a consensus about the above problems to the contribution of low coverage of vaccination, the problem still persisted with much little improvement posing a challenge to the country health care delivery system(11, 20, 21). Therefore 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 determinates 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.