HRT has important potential public health benefits because it can delay the age of onset and reduce the risk of many chronic diseases. However, the inherent complexity of HRT risk and benefit analyses necessary for a woman to make an informed decision about whether to use HRT presents a significant challenge. To date, deci sion-aid interventions have primarily been evaluated with clinic-based samples of women who may or may not represent the needs of women in the community. This paper reports data from the baseline assessment of participants in a randomized controlled trial designed to eva lu ate the efficacy of a tai lored decision-aid intervention on HRT decision making. Of the community sample of 581 Women ages 45-54 who were interviewed by telephone, 318 were determined to be menopausal and were included in this report. Fully one-third (n = 104) of these menopausal women were undecided abou t using HRT; 55% (n = 176) had decided to use HRT and 12% (n = 38) had decided against using HRT. Women who were undecided about HRT use were significan tly different from the other two groups in their income, stage of menopause, prior use of HRT, hysterectomy rates, a ttitudes abou t menopause, and knowledge about HRT. This paper describes directions and strengths of these differences. Findings sugges t that future decision-aid interventi ons with potential for dissemination outside of clinica l set tings would benefit this undecided group. H ormone Replacement Therapy (HRT) has important public health benefits, because it can delay the age of onset and reduce the risk of many chronic diseases. The potential benefits associa ted with HRT include a reduced risk of osteoporosis, heart disease, Alzheimer's disease, ovarian cancer, and colon cancer.1-7 Conversely, the potential risks associated with HRT include an increased risk of breast cancer, endometrial cancer (if unopposed with a progesterone), and thromboembolic disease.8-10 The inherent complexity of assessing the personal risks and benefits of HRT that are necessary to make an informed decision presents a significant challenge for women. Evidence suggests that women know more about the po_tential risks, such as breast cancer, than about the proven benefits, such as preventing osteoporosis.11-12 Thus, women may give more weight to the potential risks of HRT than the proven benefits. Several studies have reported that women who use HRT are: better educated, have higher income, more likely to have had a surgical menopause, less likely to have a family history of breast cancer, and have more frequent contact with physicians.13-15 Alternatively, women who choose not to use HRT report cos t, physician advice, unwanted side effects, inconvenience, and fear of the risks, especially the risk of breast cancer, as barriers to use of HRT.16 However, little is known about the important group of women who are undecided about HRT use. Women who are w1decided may be different both in terms of their attitudes and knowledge about menopause as well as their understanding of the risks and benefits of HRT. These women may need more information, or assurance from their health care providers, that there is no one decision right for every woman. The objective of this paper is to compare menopausal women who were undecided about HRT with those who have already made a decision to either use or not use HRT. Women who were not eligible to be prescribed HRT because the decision to use HRT was not yet salient (eg., they were not menopausal) were excluded. Identifying factors associa ted with being undecided about HRT use could guide the development of decision-aid interventions for women in clinical and community settings. BASTIAN: HORMONE REPLACEMENT THERAPY 331