OBJECTIVE: To examine whether women who were using postmenopausal hormone therapy (HT) before publication of Women’s Health Initiative findings about risks associated with HT had been informed about the findings once published; and to estimate how knowledge of these findings was associated with their decision to discontinue HT. METHODS: We performed a telephone survey of 670 female members of a large health maintenance organization, aged 50-69 yr, who had regularly used HT from July 1, 2001, through June 30, 2002. RESULTS: Most women (93%) reported hearing about the new findings; however, only 57% considered the quality of this information to be good, regardless of its source: mass media (21%), the health plan (32%), or a health care practitioner (34%). Women’s knowledge of Women’s Health Initiative findings was generally poor; 64% did not know what the findings were, 7% were unsure of their knowledge, 6% had incorrect knowledge, and 23% had correct knowledge of Women’s Health Initiative findings. On a simple, five-question, true-or-false quiz about HT risks, 30% of respondents answered four to five questions correctly. Although not well informed, 56% reported attempting to discontinue HT in the 6 to 8 months after July 2002. Our multivariable model included five statistically significant predictors of attempting to stop HT: having been sent a letter about Women’s Health Initiative findings (odds ratio [OR] 2.7; 95% confidence interval [CI] 1.8, 3.9), reporting good-quality information from media (OR 2.1; 95% CI 1.3, 3.3), having started HT for health promotion (OR 2.0; 95% CI 1.2, 3.3), using a lower-than-standard dosage of estrogen (OR 1.9; 95% CI 1.1, 3.1), and correctly answering four or more items on the HT quiz (OR 1.9; 95% CI 1.2, 2.8). CONCLUSION: During the 6-8 months after publication of Women’s Health Initiative trial findings, most regular postmenopausal HT users tried to stop using HT, despite not being well informed about the Women’s Health Initiative findings.