Objective: To understand the basis of the Callista Roy Adaptation Model, adaptive experiences of women who have undergone a mastectomy. Methods: Phenomenological methodology was the selected path. Data were collected 1. er Trimestre 2019 • Año XXIII-N.° 53 Results: Alterations suffered by women with mastectomies, include those concerning the adaptation modes defined by Roy Theory, which are physiological, selfconcept, role function and interdependence. Conclusions: The loss of one or both breasts for women represents a major change in their lives, which may affect, the way she perceives herself, her system of beliefs and values. Adaptation experiences identified through the responses of the participants, most of them attributed to religion, as an important motivation to continue their lives.