RESUMEN
Breast cancer remains significantly distressing and produces profound changes in women's lives. Spirituality is an important resource at the time of diagnosis and treatment decisions. This qualitative study aimed to explore the spiritual experience of women diagnosed with breast cancer and the considerations of spirituality in health care using the existential phenomenology approach. The sampling procedure was intentional, based on the study's exclusion and inclusion criteria. Forty women participated in individual interviews. The research was conducted in the outpatient clinic of a reference federal university hospital in South-Eastern Brazil. Throughout the research process, ethical principles were carefully followed. Five themes were identified: (1) meaning of spirituality-source of spiritual strength, (2) well-being in the relationship with God, (3) well-being in religious fellowship, (4) values and purpose of life-meaning in life, and (5) spirituality as a foundation to continue. Respect for patient's spiritual values was recognised as a fundamental principle in health care. Spirituality was revealed as a source of support during the complex process of being diagnosed with breast cancer. Thus, health care professionals that value and encourage spirituality are needed, favouring better patient response to the diagnosis.