Introduction: The under-five mortality rate in Indonesia and East Java in 2021 shows a downward trend from 2020, with the main cause of under-five mortality being infectious diseases such as pneumonia and diarrhea. One of the factors that contributed to this was the increase in complete immunization coverage for babies in previous years; however, in the 2021 and 2022 periods in Indonesia and East Java, there was a significant decline in the number of complete immunization coverage. Community behaviour regarding improving health, in this case, immunization, is determined by many factors, one of which is the knowledge and attitudes of the mothers of toddlers themselves. Objective: Analyzing the correlation between the knowledge and attitudes of mothers of toddlers regarding immunization and compliance with providing complete routine immunization in Wage Village, Taman District, Sidoarjo Regency, East Java, Indonesia. Method: This research used quantitative methods with a cross-sectional approach. Data was collected through questionnaires given to 90 mothers of toddlers aged 24-59 months in Wage Village who had a Healthy Way Card (KMS) or Maternal and Child Health Book (KIA); the sample size was calculated using the Compare Two Proportions formula, sampling techniques using Purposive Consecutive Sampling, and Fisher's Exact test was used to see the correlation between the two variables. Results: The results of this study show that there is no significant correlation between the knowledge of mothers of toddlers about immunization and compliance with providing complete routine immunization (p=0.434), and there is no significant correlation between the attitude of mothers of toddlers about immunization and compliance with providing complete routine immunization (p=1.000). Conclusion: The results of this study indicate that neither the knowledge nor attitudes of mothers of toddlers regarding immunization have a significant correlation with compliance in providing complete routine immunization in Wage Village, Taman District, Sidoarjo Regency. Efforts to increase immunization compliance need to focus on other aspects, such as cross-sectoral cooperation, accessibility of health services and more comprehensive education programs for mothers of toddlers, families and the community.