Chest pain in children can be a common presentation with causes including idiopathic, musculoskeletal and respiratory conditions, but is rarely cardiac in origin. However, in rare cases, it may indicate life-threatening conditions such as anomalous origin of coronary arteries. Among these, anomalous origin of the left coronary artery from the right sinus (ALCRSV) with an intramural and inter-arterial course is particularly concerning due to its association with myocardial ischemia and sudden cardiac death. We present the case of a previously healthy seven-year-old girl who experienced an episode of chest pain and syncope, initially misattributed to heat syncope. On her second presentation, she was acutely unwell with signs of central cyanosis and ischemic changes on ECG. Further investigation with echocardiography revealed a suspected coronary anomaly. She was transferred to a specialist centre where a diagnosis of the left main coronary artery arising from the right sinus of Valsalva was confirmed. The patient underwent successful surgical correction, including coronary unroofing and reimplantation, and was started on spironolactone and aspirin. Her recovery was uneventful, and she was discharged with a scheduled follow-up. ALCRSV is a rare but serious congenital coronary anomaly that can present with exertional chest pain and syncope in children. Diagnosis is often challenging due to nonspecific symptoms and inconclusive initial investigations. However, timely recognition and surgical intervention can prevent fatal outcomes. This case emphasises the importance of maintaining a high index of suspicion for coronary anomalies in paediatric patients presenting with exertional syncope or ischemic ECG changes, even in the absence of prior cardiac history.