Background <p>The de Winter electrocardiographic (ECG) pattern is considered an ST-elevation myocardial infarction (STEMI) equivalent and is most commonly associated with acute proximal left anterior descending (LAD) occlusion. However, de Winter-like anterior ST–T morphology may occur without complete LAD occlusion and may coexist with multivessel coronary artery disease; therefore, ECG–angiography correlation is essential.</p> Case presentation <p>A 60-year-old male with type 2 diabetes presented with 2&#xa0;h of exertional chest discomfort accompanied by dizziness, diaphoresis, and fatigue. Initial ECG showed inferior ST-segment elevation (II, III, aVF) with concomitant de Winter-like changes in the precordial leads (V2–V6). Based on the inferior STEMI criteria, emergent coronary angiography was recommended, but the patient declined immediate percutaneous coronary intervention and received conservative medical therapy. Delayed angiography on day 4 demonstrated near-total mid-right coronary artery (RCA) occlusion (culprit lesion) and severe proximal LAD stenosis without complete occlusion. PCI with stent implantation was successfully performed in the RCA. The patient remained haemodynamically stable and was discharged with a plan for staged LAD revascularisation after clinical stabilisation, although no definitive intervention timing was documented during 1-month follow-up. At follow-up, clinical recovery was favourable, with persistent ECG changes and mildly impaired left ventricular diastolic function.</p> Conclusion <p>This case demonstrates that de Winter-like anterior ECG morphology may coexist with inferior STEMI in multivessel coronary artery disease. Such morphology should not be interpreted in isolation as evidence of LAD occlusion, but integrated with angiographic findings and the overall ischaemic context. When inferior STEMI criteria are present, standard emergent reperfusion pathways should be prioritised irrespective of concurrent anterior ST–T morphology.</p>