BACKGROUND: The reasons behind teenage pregnancy and marriage in Indonesia are the lack of life skills and low self-efficacy. Teenagers with a lack of life skills are more likely to be influenced by their peers, in this case, to have sex before marriage. Teenage pregnancy often leads to a high rate of maternal and infant mortality and high-risk infants. AIM: This study aimed to identify internal and external factors influencing adolescent pregnancy prevention behavior. METHODS: This quantitative study with a cross-sectional design recruited 398 adolescents using a multistage sampling technique. Chi-square test and logistic regression test were employed with p < 0 xss=removed xss=removed>