Imunisasi dasar merupakan langkah penting dalam mencegah penyakit berbahaya pada bayi. Namun, lebih dari 1,8 juta anak Indonesia tidak mendapat imunisasi rutin lengkap selama 6 tahun terakhir, dari 2018 sampai 2023. Penelitian ini bertujuan untuk menganalisis hubungan antara pengetahuan dan kepatuhan ibu dengan kelengkapan imunisasi dasar pada bayi usia 9-18 bulan. Metode penelitian menggunakan pendekatan kuantitatif dengan desain retrospektif, penelitian dilakukan dengan teknik purposive sampling dengan jumlah sampel 215. Data dikumpulkan menggunakan kuesioner dan dianalisis dengan uji chi-square. Hasil penelitian menunjukkan bahwa mayoritas responden berusia 19-59 tahun (100%), berpendidikan SMA (50,2%), dan bekerja sebagai ibu rumah tangga (67,9%). Sebanyak 94,4% ibu memiliki pengetahuan baik tentang imunisasi, 90,2% patuh terhadap jadwal imunisasi, dan 92,1% bayi menerima imunisasi dasar lengkap. Hasil penelitian didapatkan ada hubungan antara pengetahuan ibu dengan kelengkapan imunisasi dasar dan ada hubungan antara kepatuan ibu dengan kelengkapan imunisasi dasar. Upaya peningkatan pengetahuan dan kepatuhan ibu dapat dilakukan melalui penyuluhan kesehatan dan pemanfaatan media informasi untuk meningkatkan kesadaran ibu terhadap pentingnya imunisasi dasar. Kata Kunci: Pengetahuan, Kepatuhan, Kelengkapan Imunisasi.

Basic immunization is an important step in preventing dangerous diseases in infants. However, more than 1.8 million Indonesian children have not received complete routine immunizations for the past 6 years, from 2018 to 2023. This study aims to analyze the relationship between maternal knowledge and compliance with the completeness of basic immunization in infants aged 9-18 months. The research method uses a quantitative approach with a retrospective design, the study was conducted using a purposive sampling technique with a sample size of 215. Data were collected using a questionnaire and analyzed using the chi-square test. The results showed that the majority of respondents were aged 19-59 years (100%), had a high school education (50.2%), and worked as housewives (67.9%). A total of 94.4% of mothers had good knowledge about immunization, 90.2% were compliant with the immunization schedule, and 92.1% of infants received complete basic immunization. The results of the study showed that there was a relationship between maternal knowledge and the completeness of basic immunization and there was a relationship between maternal compliance and the completeness of basic immunization. Efforts to increase maternal knowledge and compliance can be carried out through health education and the use of information media to increase maternal awareness of the importance of basic immunization. Keywords: Knowledge, Compliance, Completeness of Immunization.