The prime purpose of this paper is to assess the social representations created by women who have had breast cancer, and to discuss the disease, its etiology and treatment. We developed the theme theoretically, based on four perspectives: biological, psychosomatic, psychosocial and multi-factorial. We performed field research of a qualitative nature, studying ten cases of women who had breast cancer in the 35 to 50 age group and had undergone a mastectomy, could have done mammary reconstruction or not, and who participated as members of a support association to women with breast cancer in Niterói city, Rio de Janeiro State. As an instrument of this research, we used an identifying questionnaire and semi-focused interviews with those women individually and later with their relatives, based on a previously prepared script. In order to assess the obtained data, we used intra-subject and inter-subject discourse analysis. In the former, in each case we looked to identify the interviewee s perception of the disease, its etiology and the repercussions of cancer treatment on her female identity. In the latter, we created ten analytical categories. The results showed that women are apprehensive of cancer as life threatening and a risk, that breast removal in most cases affects the corporal and female identity, and that contracting the disease causes many changes in their lives.