Tetanus neonatorum is one of the crucial health problems, especially in countries with low coverage of Tetanus Toxoid (TT) immunization such as Indonesia. In 2020, the coverage of TT immunization for pregnant women in Indonesia decreased from 2019. This study aims to determine the behavioral determinants of pregnant women toward TT immunization. This research is a quantitative study with an analytic design with a cross-sectional approach. The questionnaire was filled out by 137 pregnant women in the District of West Tapalang. The data from this study were analyzed using the chi-square test and multiple logistic regression. The results indicated that there were two determinants related to the behavior of pregnant women towards TT immunization, including knowledge (p=0.018) and perception of barriers (p<0.001). Multivariate analysis showed that the dominant determinant influencing the behavior of pregnant women towards TT immunization was the perception of barriers (OR=10.046). Therefore, only the knowledge and perceived barrier variables were related to the behavior of pregnant women towards TT immunization, where the perceived barrier was identified as the dominant variable. It is hoped that the Puskesmas staff will increase the coverage of TT immunization for pregnant women by routinely sweeping the status of TT immunization and providing education about TT immunization by involving husbands as an essential target in the education process.