A semistructured measure was developed from early descriptive work by Lipowski to elicit the meaning of breast cancer using eight preset categories: challenge, enemy, punishment, weakness, relief, strategy, irreparable loss, and value. This measure was applied in two studies: a cross-sectional survey of 1012 Canadian women at various points after diagnosis and a follow-up study 3 years later of 205 women from the previous study who were close to the time of diagnosis at the first testing. The majority of the 1012 women chose "challenge" (57.4%) or "value" (27.6%) to describe the meaning of breast cancer, whereas fewer chose the more negative "enemy" (7.8%) or "irreparable loss" (3.9%). At the 3-year follow-up assessment, 78.9% of the women who had indicated positive meaning by their choices of "challenge" or "value" did so again. Verbal descriptions provided by the women were congruent with those reported in previous qualitative studies of meaning in breast cancer with respect to the two most prevalent categories: challenge and value. At follow-up assessment, women who ascribed a negative meaning of illness with choices such as "enemy," "loss," or "punishment" had significantly higher levels of depression and anxiety and poorer quality of life than women who indicated a more positive meaning. The meaning-of-illness measure provides an approach that can be applied in large surveys to detect women who ascribe less positive meaning to the breast cancer experience, women who may be difficult to identify in the context of small, qualitative studies.