May-Thurner syndrome (MTS) traditionally refers to compression of the left common iliac vein between the right common iliac artery and the vertebral body. However, iliac vein compression is common in asymptomatic individuals, and the contemporary concept of nonthrombotic iliac vein lesions (NIVLs) emphasizes that anatomic compression alone does not constitute an indication for treatment. Successful endovascular therapy depends on appropriate patient selection and accurate assessment of clinically significant venous outflow obstruction. Intravascular ultrasound is valuable for lesion characterization, assessment of stenosis severity, stent sizing, selection of landing zones, and confirmation of final stent expansion. Durable reconstruction requires complete coverage of the diseased segment, appropriate stent sizing and expansion, adequate proximal outflow with minimal unnecessary coverage of the contralateral common iliac vein ostium, and adequate distal inflow. In post-thrombotic obstruction, reconstruction may need to extend across the inguinal ligament into the common femoral vein when required to reach a satisfactory inflow segment. This review provides a practical framework for the evaluation and endovascular management of MTS and NIVLs, with emphasis on procedural decision-making relevant to interventional radiologists.