RESUMEN
BACKGROUND: Breast cancer is the leading cause of death from cancer in the female population; consequently, there are multiple prevention campaigns. Within these campaigns, a special emphasis is given on promoting monthly breast self-examination; however, many women have never received formal education on proper method of self-examination. OBJECTIVE: To establish if the educational intervention we propose improves the breast self-examination technique. MATERIAL AND METHODS: A descriptive longitudinal study that included 52 women aged 20-40 years, attending a Family Medicine Unit of the Mexican Institute of Social Security, who were evaluated about self-examination technique before and after educational intervention, measured on a scale of 0 to 16. Statistical analysis was made with descriptive statistics and Student's t test. RESULTS: The mean age was 30.76 ± 5.87 years. The mean baseline score was 3.13 ± 2.55. The final average score after a month of the educational intervention was 10.69 ± 2.74, which represents an increase in average score of 7.55 ± 3.53. There was a significant increase in assessment scores after the educational intervention (p < 0.001). CONCLUSIONS: "Supervised breast self-examination" technique showed an increase in the ability of self-examination in patients. It can be considered an effective complementary method of teaching breast self-examination.