Chronic total occlusions (CTO) are frequently found in clinical practice, yet they are still undertreated, despite the frequent presence of clinical indications for revascularization. The presence of a CTO is a frequent cause of incomplete revascularization, which has been associated with worse long-term outcomes (including mortality), compared to complete revascularization. Such low rates of attempted revascularization can be attributed to a common misconception about the lack of benefit of CTO revascularization, combined with historically lower success rates and higher complication rates of CTO percutaneous coronary intervention. However, modern percutaneous techniques, devices and algorithms now allow successful CTO revascularization in approximately 90% of cases. Additionally, state-of-the-art surgical techniques offer complete revascularization and provide excellent long-term patency rates. The present review provides a critical appraisal of the literature supporting the rationale, indications, modalities and state-of-the-art techniques of CTO revascularization by both percutaneous and surgical approaches. © 2017 Elsevier B.V.