ABSTRAKLatar Belakang: Pencapaian imunisasi dasar lengkap di Puskesmas Sawah Lebar belum memenuhi target. Salah satu penyebab belum tercapaianya target tersebut yaitu karena factor ibu dalam mengimunisasikan anaknya dan faktor pendidikan serta pengetahuan ibu dalam hal Kesehatan terutama Imunisasi. Penelitian ini dilakukan untuk menganalisis hubungan faktor ibu dalam pencapaian imunisasi dasar lengkap di wilayah kerja Puskesmas Sawah Lebar Kota Bengkulu.Metode : Penelitian dilakukan dengan rancang bangun cross sectional. Subyek penelitian diambil dari populasi dengan cara simple random sampling. Variabel bebas pada penelitian ini adalah usia ibu, tingkat pendidikan ibu, pekerjaan ibu, tingkat pengetahuan ibu, kepercayaan ibu dan sikap ibu.Hasil : Hasil Penelitian menunjukan bahwa variabel yang berhubungan dalam pencapaian imunisasi dasar lengkap yaitu tingkat pendidikan ibu (p=0,020), tingkat pengetahuan ibu (p=0,000), kepercayaan ibu (p=0,000) dan sikap ibu (p=0,000). Sedangkan variabel usia ibu dan pekerjaan ibu tidak berhubungan dalam pencapaian imunisasi dasar lengkap karena nilai p>0,05.Simpulan : Dari penelitian ini faktor yang berhubungan dalam pencapaian imunisasi dasar lengkap yaitu tingkat pendidikan ibu, kepercayaan ibu, sikap ibu dan tingkat pengetahuan ibu. Sangat diperlukan pengetahuan ibu dalam memahami penyampaian informasi terutama tentang Imunisasi, dan peran petugas kesehatan sangat diperlukan dalam memberikan penjelasan kepada ibu terkait kejadian pasca imunisasi sehingga ibu percaya bahwa imunisasi berdampak baik bagi anak.Kata Kunci: Imunisasi Dasar, Kepercayaan Ibu, Sikap Ibu, Tingkat Pendidikan Ibu, Tingkat Pengetahuan Ibu. ABSTRACTBackground The achievement of complete basic immunization at the Sawah Lebar Health Center has not met the target. One of the causes of not achieving this target is the mother's factor in immunizing her child and the mother's education and knowledge in terms of health, especially immunization. This study was conducted to analyze the relationship between maternal factors in achieving complete basic immunization in the working area of the Sawah Lebar Community Health Center, Bengkulu City.Methods: The study was conducted with a cross-sectional design. Research subjects were taken from the population by means of simple random sampling. The independent variables in this study were mother's age, mother's educational level, mother's occupation, mother's level of knowledge, mother's beliefs and mother's attitude.Results: The results showed that the variables related to achieving complete basic immunization were the mother's education level (p=0.020), mother's level of knowledge (p=0.000), mother's belief (p=0.000) and mother's attitude (p=0.000). Meanwhile, the variable mother's age and mother's occupation were not related to achieving complete basic immunization because the p value was > 0.05.Conclusion: From this study the factors related to achieving complete basic immunization were the mother's education level, mother's beliefs, mother's attitude and mother's level of knowledge. Mother's knowledge is very much needed in understanding the delivery of information, especially about immunization, and the role of health workers is very necessary in providing explanations to mothers regarding post-immunization events so that mothers believe that immunization has a good impact on children.Keywords: Basic Immunization, Mother's Belief, Mother's Attitude, Mother's Education Level, Mother's Knowledge Level.