Abstract: This report contains a brief summary of the health-related quality of life findings for 11,064 women taking part in the National Surgical Adjuvant Breast and Bowel Project's P-1 trial. Women taking part in this trial of tamoxifen versus placebo for breast cancer prevention were ≥35 years old and predominantly white, well educated, and middle class, with a strong professional and technical orientation. Key findings included a lack of difference between the tamoxifen and placebo arms with regard to depression, overall physical or mental quality of life, and weight gain. The tamoxifen arm did show consistent increases in vasomotor (hot flashes) and gynecological (vaginal discharge) symptoms, as well as difficulties in certain domains of sexual functioning. It is concluded that an informed discussion with a woman considering tamoxifen therapy should include these points in the risk-benefit discussion.