Acute chest pain is one of the most common reasons for emergency department (ED) visits, yet only a small fraction of cases are due to acute coronary syndrome (ACS), creating a diagnostic challenge. Traditional evaluation methods including clinical assessment, electrocardiography, cardiac biomarkers, and risk scores, lack early sensitivity and fail to directly visualize coronary anatomy, often leading to prolonged observation and unnecessary admissions. Coronary computed tomography angiography (CCTA) offers a rapid, noninvasive solution by providing high-resolution visualization of coronary arteries and atherosclerotic plaque, achieving sensitivity above 95% and negative predictive value exceeding 99% for ruling out obstructive coronary artery disease (CAD). Advances in scanner technology, dose reduction, and workflow integration have established CCTA as a feasible, safe, and efficient ED diagnostic tool. Randomized trials demonstrate that CCTA-guided pathways reduce length of stay, hospital admissions, and healthcare costs without compromising safety, while improving triage and enabling early discharge of low-to-intermediate-risk patients. Beyond acute rule-out, CCTA provides valuable prognostic insight through plaque characterization and risk stratification, guiding preventive therapy. Despite challenges such as motion artifacts, heavy calcification, and incidental findings, optimized protocols and guideline-based patient selection ensure high diagnostic accuracy and safety. Emerging innovations, including CT-derived fractional flow reserve, AI-assisted plaque quantification, and photon-counting CT, promise further gains in precision and efficiency. Major cardiology societies now recommend CCTA as a first-line imaging modality for selected chest-pain patients. Collectively, evidence supports CCTA as a transformative, rapid, and comprehensive approach for ruling out ACS, improving patient outcomes, and enhancing resource stewardship in the emergency department.