In Indonesia the immunization program is resolved to achieve the universal child immunization (UCI). In 1990 the International agreement was made to give the complete immunization to all children. The children with incomplete immmunization status could increase the KLB PD31 opportunities. The purpose of the research was to achieve the illustration of incomplete baby immunization and to determine factors related to the incomplete child immunization in Sub district Suka Makmur, Aceh Besar District. It was an analytic study using a cross sectional design. The respondents were 96 mothers who had 12-23 month babies. The risk factors were age, education, occupation, income, knowledge on immunization, age at the first time contact. Data were collected by structured interview and analized by Odds Ratio (OR). Results showed the prevalence of incomplete immunization child status was about 38.6%. The age of first time contact, the mother's knowledge about immunization and the distance between the house and the immunization service centre were associated with the child immunization status.