Background: Percutaneous coronary intervention (PCI) has become the cornerstone of coronary artery disease management. However, angiography alone provides limited information regarding plaque morphology, vessel dimensions, and stent optimization. Optical coherence tomography (OCT), a high-resolution intracoronary imaging modality, has revolutionized coronary intervention planning by providing near-histological visualization of vessel architecture. Objective: To evaluate the clinical utility of OCT in coronary intervention planning, lesion assessment, stent sizing, procedural optimization, and long-term patient outcomes. Methods: A comprehensive review of contemporary literature, randomized controlled trials, registries, and expert consensus documents was conducted. Major studies evaluating OCT-guided PCI were analyzed with respect to procedural success, stent expansion, clinical outcomes, and complication reduction. Results: OCT provides superior spatial resolution (10–20 μm) compared with intravascular ultrasound (IVUS), enabling detailed visualization of plaque characteristics, thrombus burden, calcium distribution, and stent apposition. Multiple clinical trials demonstrate improved procedural optimization and reduced adverse cardiovascular events when OCT guidance is employed. Conclusion: OCT has emerged as an indispensable imaging modality in contemporary coronary intervention planning, facilitating precision PCI and improved patient outcomes.