Background and Purpose: Heart disease is the leading killer of women and remains poorly recognized in highrisk groups. We assessed baseline knowledge gaps and efficacy of a survey-based educational intervention. Methods: Four hundred seventy-two women in clinical settings completed pre-/post-surveys for knowledge of: heart disease as the leading killer, risk factors (general and personal levels), heart attack/stroke symptoms, and taking appropriate emergency action. They received a clinic-based educational intervention delivered by healthcare professionals in the course of their clinical care. Change score analyses tested pre-/post-differences in knowledge after the educational intervention, comparing proportions by race, ethnicity, and urban/nonurban status. Results: Knowledge and awareness was low in all groups, especially for American Indian women ( p < 0.05). Awareness was overall highest for heart disease as the leading killer, but it was the lowest for taking appropriate action (13% of Hispanic, 13% of American Indian, 29% of African American, and 18% of nonurban women; p < 0.05). For all women, knowledge of the major risk factors was low (58%) as was knowledge of their personal levels for risk factors (73% awareness for hypertension, 54% for cholesterol, and 50% for diabetes). The intervention was effective (% knowledge gain) in all groups of women, particularly for raising awareness of: (1) heart disease as the leading killer in American Indian (25%), Hispanic (18%), and nonurban (15%) women; (2) taking appropriate action for American Indian (80%), African American (64%), non-Hispanic (55%), and urban (56%) women; (3) heart disease risk factors for Hispanic (56%) and American Indian (47%) women; and (4) heart disease and stroke symptoms in American Indian women (54% and 25%, respectively). Conclusions: Significant knowledge gaps persist for heart disease in high-risk women, suggesting that these gaps and groups should be targeted by educational programs. We specify areas of need, and we demonstrate efficacy of a clinic-based educational intervention that can be of utility to busy healthcare professionals.