Abstract
This study examines the relationship between mothers' knowledge of basic immunization and the completeness of basic immunization in infants in the working area of Kalimas Primary Health Center, Pemalang Regency, Indonesia. An analytical observational design with a cross-sectional approach was used. The sample consisted of 68 mothers with infants aged 9–12 months, selected through total sampling. Data were collected using a validated questionnaire and analyzed with univariate and bivariate Chi-Square tests. Most respondents had moderate knowledge (41.2%), while good and poor knowledge each accounted for 29.4%. Complete basic immunization was found in 52.9% of infants, and 47.1% were incomplete. The Chi-Square test showed a significant association between maternal knowledge and immunization completeness (χ²=22.586; p=0.000). Mothers with good knowledge were far more likely to have infants with complete immunization status (90.0%) compared with mothers with poor knowledge (15.0%). These findings indicate that maternal knowledge is a determinant factor of basic immunization completeness. Enhanced health education delivered by health workers and community health cadres is recommended to strengthen maternal knowledge and support achievement of complete basic immunization coverage in rural working areas such as Kalimas.