I Immunisation is a way to induce immunity against a disease . Immunization plays an important role in health development in Indonesia. Indonesian ministry has been developed immunization programs that include BCG , DTP , hepatitis B , polio and measles immunization. These immunization must be given to children as a primary prevention from several diseases. Several factors can affect the given of complete basic immunization. The aim of this study is to determine the relationship between the level of mother's education and knowledge to complete basic immunization in toddlers at Kelurahan Tomang Government Clinic, West Jakarta. This study used an observational study with cross- sectional research design. Samples are included as many as 203 mothers who have toddlers. Data were collected by interview using a questionnaire that includes mother’s education, age, family income, and mother's knowledge about immunizations, as well as the completeness of the basic immunization in toddlers . Analyses were performed using chi-square analysis and significance level used was 0.05. SUnivariate analysis showed that 46,3 % mothers had low education, 50,7 % moderate, and 3 % high. As much as 3.9 % mothers had low knowledge about immunization, while it was 96.1 % mothers with good knowledge . Chi-square analysis showed that there was no relationship ( p > 0.05 ) between the level of mother’s education with complete basic immunization in toddlers, in the meantime the mother's level of knowledge has a relationship ( p < 0.05 ) with it. Other factors such as mother’s age and family’s socio-economic are also not related to the given of complete basic immunization. The study showed that most of mothers have moderate education and high knowledge about immunization . Based on 4 factors that were investigated, mother’s level of education, knowledge, age, and socio-economic, only the level of mother’s knowledge has a significant association or relationship with complete basic immunization in toddlers.