To evaluate the effectiveness of an Avatar application for educating people with acute coronary syndrome (heart attack). A lack of understanding of Acute Coronary Syndrome symptoms and appropriate responses often contribute to delay in seeking medical treatment. A single-centre, non-blinded, pragmatic randomized controlled trial. Seventy Acute Coronary Syndrome patients were randomly assigned to the intervention (Avatar application) or usual care groups. Participants were followed up at 0, 1, and 6months. Tobit Growth Curve Model was used to analyse the primary outcome-symptom knowledge; and the secondary outcomes-attitudes and beliefs. Heart attack action plan implementation and health care utilisation were analysed using Chi-square and Mann-Whitney U test. Of the 70 participants, 63% were male and the mean age of the participants was 64.7 (SD 11.7) years. Sixty-six (94.2%) participants completed follow-up. Between group differences on acute coronary syndrome (ACS) Response Index scores were statistically significant at 1-month and 6-month follow-ups (p<.01). The intervention group had a significant improvement in symptom knowledge, attitudes, and beliefs over the 6-month period (p<.001, p=.009, p<.001 respectively); and no significant improvement in the usual care group participants (p=.152, p=.068, p=.228). For healthcare use, at follow-up, there was a significant difference in ambulance use, between the intervention group and the usual care group (33.33% vs. 18.18%, p=.008; cardiac: 88.89% vs. 42.86%; p=.049); 85.14% of participants reported that the application helped them to feel more confident in recognizing and responding to symptoms in the future. The education app was effective in improving individuals' ACS knowledge, attitudes, and beliefs. A large multi-centre trial with a longer follow-up to evaluate the intervention's effectiveness on clinical outcomes will be our next step in evaluation. The content of AVATARS (Nurse Cora) app can be translated into different languages and evaluated for patients from different health settings and linguistic backgrounds. This study has been registered with Australian New Zealand Clinical Trials Registry (ANZCTR). The trial registration number is ACTRN12616000803493.