Duplex ultrasound of the abdominal and pelvic veins is a safe, non-invasive, and highly accurate imaging modality used to assess for venous compression syndromes. This technique enables real-time evaluation of venous blood velocity, vessel diameter, and the direction of flow. By performing the examination in multiple patient positions—including supine, reverse Trendelenburg, and standing—sonographers can document hemodynamic changes that may suggest positional or anatomical venous compression. This protocol is designed to guide sonographers through the anatomical landmarks necessary for a comprehensive assessment of the iliac, renal, and gonadal venous systems. Careful adherence to these guidelines supports accurate diagnosis and aids in the detection of clinically significant venous abnormalities.