<![CDATA[Breast Self-Examination (BSE/SADARI) is a simple and cost-effective method for the early detection of breast cancer. However, many female adolescents still do not practice BSE regularly. This study aimed to analyze the relationship between knowledge level, information sources, and BSE behaviour among female students at SMA Pelita Rantepao. A quantitative analytic study with a cross-sectional design was conducted involving 81 Grade XI female students selected through total sampling. Data were collected using validated self-administered questionnaires and analyzed using descriptive statistics and the Chi-square test. The results showed that most respondents had good knowledge (76.5%) and adequate information sources (53.1%), yet the majority demonstrated poor BSE behaviour (67.9%). No significant association was found between knowledge level and BSE behaviour (p = 0.537). In contrast, information sources were significantly associated with BSE behaviour (p = 0.001). Respondents with adequate access to BSE information had higher odds of demonstrating good BSE behaviour than those with inadequate information sources (OR = 6.300; 95% CI: 2.067–19.204). This indicates a statistically significant association between information sources and BSE behaviour, with the confidence interval excluding 1. These findings indicate that access to reliable health information plays a more important role than knowledge alone in promoting BSE practice among adolescent girls. Strengthening school-based health education and improving access to credible information may enhance early breast cancer prevention behaviours.]]>
