This qualitative study uses an exploratory research design that incorporates both grounded theory and phenomenological approaches in order to gain insight into the meaning of yoga in relation to coping with breast cancer. The study focuses on the individual, lived experience and relies on in-depth interview strategies to capture the subjects' sensations and perceptions of the practice and utility of yoga over the duration of time. By interviewing women who practice yoga for different spans of time, several aspects are explored: if the length of time affects any observed changes; if transitional stages in yoga progression can be identified, and if so, what influences these changes; and how differing stages of yoga practice affect a woman's coping with breast cancer. The data generated a narrative account of common themes that identify four stages of yoga commmitment and eight variables that mediate change and suggest engagement, advancement, a deepening relationship to yoga, and a gradual identity transformation. In addition, prevailing themes regarding yoga's meaning and impact on coping with breast cancer come to light. As dominant themes emerged from the women's stories, health behavior change theories were initially considered to enhance understanding of the emergent themes. Important constructs from social cognitive, planned behavior, and transtheoretical theories were found to be salient within the context and findings of this study, but no one theory was sufficient to understand the themes that emerged. In addition, principles of structural symbolic interactionism and identity theory were similarly identified that could explicate aspects of a noted identity transformation among the respondents. In the final analysis, where health behavior theories fall short, concepts of identity theory complete an explanation of the transitions that occur as the yoga practice deepens. Combining constructs of both behavior change and identity theories may represent a new theory that more accurately reflects the observed mechanisms and emergent themes expressed by the respondents as they use yoga to cope with breast cancer.