Background: Good knowledge of ischemic heart diseases (IHD), if combined with positive attitudes and correct beliefs, may contribute effectively to patients and bystanders’ decisions at the time of cardiac events. Therefore, the aim of this study was to evaluate Jordanian adults’ knowledge, attitudes, and beliefs about ischemic heart diseases. Methods: Descriptive design was used. Convenience sample included 219 adult Jordanians who were oriented and free from mental diseases; were recruited between August and December 2012. The Modified Response Questionnaire was used to measures knowledge, attitudes, and beliefs about ischemic heart diseases as well as intended responses to any future cardiac event. Results: Fifty-two percent of the participants could name 4–6 cardiovascular risk factors. The average knowledge score for ischemic heart diseases was 63.5%, in which 44% of participants were less than the average score. Out of 20, the average attitude score was 11.9, and 43.5% of participants scored less than the average score. Out of 40, the average beliefs score was 27.14, and 55.7% of participants scored less than the average score. Married, educated, and higherincome participants have more-correct beliefs about IHD. Conclusions: The critical shortage of cardiac-related knowledge and inappropriate attitudes and beliefs among the majority of Jordanians made IHD the unrecognized killer in Jordan. Results should be utilized in the efficient design of interventional programs that aim to achieve the primary goal of improving peoples’ knowledge, attitudes, and beliefs about ischemic heart diseases. Thus, the efforts of nurses, researchers, and policy makers should focus on facing ischemic heart diseases through improvements in primary and secondary prevention, as well as cardiac rehabilitation programs in the Jordanian community.