Introduction: Sexuality is a complex area in women, especially in those who have been diagnosed with breast cancer (BC). Objective: To evaluate whether there is an association between breast cancer (BC) and sexual dysfunction (SD) in adult women in a national reference hospital of Social Security in Peru. Method and sample: We carried out an analysis in 167 women under 60 years of age, which were divided into two groups: with BC (after mastectomy and without mastectomy), and without cancer. We used the validation of the Spanish version of the Female Sexual Dysfunction Index. We made a comparison among women with BC and without cancer (A). Additionally, we carried out two exploratory comparisons: among women with BC after mastectomy and without mastectomy (B); and another among women without BC, with BC after mastectomy, and with BC without mastectomy (C). We estimated crude prevalence ra...