Breast self-examination (BSE) is a simple, free and safe technique for detecting breast cancer in its early stages. Objective: To determine if there is a relationship between the level of knowledge, attitudes and practices of BSE in women between the ages of 20 and 59 in the area of jurisdiction of the Jerusalem District Hospital - La Esperanza. Method: Observational, cross-sectional, correlational study. A survey and a checklist of BSE were applied. The Chi-Square test was used with p <0.05. Results: The level of knowledge was low in 4.87%, medium in 77.53% and high in 17.6%. Attitudes were unfavorable in 17.6% and favorable in 82.4%. The practices were adequate in 7.49% and inadequate in 92.51%. There is a statistically significant relationship between the level of knowledge and practices of BSE (x^2: 19.466; p = 0.00005), between attitudes and practices (x^2: 5.447, p = 0.0196) and be...