Background: Breast self-examination is a simple and direct, non-invasive, and low-cost screening approach for breast cancer identification. Unlike in the Western world, women in Ethiopia frequently appear late for breast cancer screening and are expected to have a very short life expectancy. In Ethiopia, the majority of studies on breast self-examination practice were limited to university students and health care workers. As a result, there was a scarcity of evidence on the practice of breast self-examination, particularly at the community level. Thus, the current study was aimed to assess the magnitude of breast self-Examination practice and associated factors among reproductive age women in West Guji zone, Southern Ethiopia. Methods: A Community based Cross-sectional study was conducted from March 1 to April 30, 2021 among 424 randomly selected Women of reproductive age in the West Guji zone. The study participants were selected using multi-stage sampling. Data were collected using pre-tested and structured Questionnaires through face-to-face interviews. A bivariable and multivariable logistic regression model was used to identify the association between dependent and independent variables. P-Value <0.25 was used to select candidate variables for Multivariable logistic regression. A p-value <0.05 and an adjusted odds ratio with 95% CI were used to identify the independent predictors of Breast Self-Examination practice. Result: Overall breast self-examination practice was 14.6 % (95% CI, 11.4-18.4). Age [AOR=1.98; 95%CI (1.06-3.70)], monthly income [AOR=2.28; 95% CI (1.09-4.78)], and having a good knowledge of breast self-examination [AOR=2.15; 95%CI (1.14-4.05)] were statistically significant predictors and positively associated with Breast self-examination practice. Conclusion: This study revealed a substantial proportion of breast self-examination practice. As a result, stakeholders in various positions should make much more effort to promote women's education, as well as encourage and advocate breast self-examination practice.