Objective: To describe spouses' reported cancer-related demands attributed to their wife's breast cancer, and to test the construct and predictive validity of a brief standardized measure of these demands. Methods: Cross-sectional and longitudinal data were obtained from 151 spouses of women newly diagnosed with non-metastatic breast cancer. Descriptive statistics were computed to describe spouses' dominant cancer-related demands, and multivariate regression analyses tested the construct and predictive validity of the standardized measure. Results: Five categories of spouses' cancer-related demands were identified, such as concerns about spouses' own functioning, wife's well-being and response to treatment, couples' sexual activities, the family's and children's well-being, and the spouses' role in supporting their wives. A 33-item short version of the standardized measure of cancer demands demonstrated construct and predictive validity that was comparable to a 123-item version of the same questionnaire. Greater numbers of illness demands occurred when spouses were more depressed and had less confidence in their ability to manage the impact of the cancer (F = 18.08 (3,103), p<0.001). Predictive validity was established by the short form's ability to significantly predict the quality of marital communication and spouses' self-efficacy at a 2-month interval. Conclusion: The short version of the standardized measure of cancer-related demands shows promise for future application in clinic settings. Additional testing of the questionnaire is warranted. Spouses' breast cancer-related demands deserve attention by providers. In the absence of assisting them, spouses' illness pressures have deleterious consequences for the quality of marital communication and spouses' self-confidence. Copyright (C) 2009 John Wiley & Sons, Ltd.