The purpose of this study was to develop and test a decision support intervention (DSI) to assist women to make and act on informed decisions that are consistent with their values in the area of menopause and hormone replacement therapy (HRT). Mode and intensity of intervention were tested in midlife women (N = 248), randomly assigned to one of three intervention formats: written information only, guided discussion, or personalized decision exercise. Data were collected over 12 months. Knowledge, decisional conflict, satisfaction with health care provider, and self-efficacy improved following intervention and were maintained for 12 months for all groups. Women's adherence to their own plans over 12 months was 59% (exercise), 76% (calcium intake), and 89% (HRT). Carefully written information is effective in promoting knowledge, adherence, and satisfaction among well-educated, interested women. It was concluded that women can understand complex information, including tradeoffs regarding treatment options. Women will adhere to their own plans, suggesting that consumer rather than provider plans may be the more appropriate gold standard for measuring adherence.