Background: Tailored educational strategies are needed for the first-time patients with acute coronary syndrome (ACS) to enhance their self-efficacy promoting long-term adherence to lifestyle modification. Objectives: To develop a tailored educational program for ACS patients and their family, and to evaluate its effectiveness on patients��� self-efficacy for lifestyle modification and compliance with self-care. Methods: One hour-length educational multimedia content was developed and included visual and audio representation such as voice-recorded texts, images, sounds, Flash animation, and video. The multimedia comprised of five learning subjects; understanding of coronary artery disease, management of hypertension and diabetes, healthy diet, stress and smoking, and exercise. A quasi-experimental pre- and post-test design was used to examine the effect of education. A total of 88 first time ACS patients (Exp. 46 and Cont. 42) who underwent percutaneous coronary intervention were recruited from September 2009 to May 2010 at a university hospital in Korea. Intervention group participated in risk factor-tailored small group education using the multimedia content and a booklet about healthy lifestyle habits (1h), telephone counseling (1 time, 30 min), and risk factor-tailored periodical cellular-phone massages (6 times, every 2 weeks) for encouragement of lifestyle modification. Control group received usual cares and counseling based on their needs while the survey conducted. The structured questionnaire was used to measure the levels of self-efficacy (19 items) and compliance with self-care (23 items). Results: Self-efficacy for lifestyle modification was significantly increased in the intervention group after 3 months compared to the control group (p<0.05). However, there was no significant difference in the level of compliance with self-care between the two groups. However, the prevalence of smoking cessation and healthy diet practice was significantly higher in the intervention group compared to the control group (p<0.05). Conclusions: A tailored educational intervention was effective in increasing self-efficacy on lifestyle modification. Longitudinal influences of the increased self-efficacy on the adherence of lifestyle changes should be assessed to identify its motivational effect.