May-Thurner syndrome (MTS)-also termed iliac vein compression syndrome, Cockett syndrome, or iliocaval compression syndrome -is caused by the compression of the left common iliac vein lumen due to pressure of the right common iliac artery as it crosses anteriorly. May-Thurner syndrome is usually diagnosed in autopsy studies and incidence of it varies between 22% and 32%. May-Thurner syndrome-related deep venous thrombosis (DVT) is only 2% to 3% of all lower extremity DVTs. May-Thurner syndrome may be asymptomatic or may cause leg swelling, varicosities, DVT, chronic venous stasis ulcers, and more serious complications, such as pulmonary embolism or phlegmasia cerulea dolens. The treatment is aimed to reduce symptoms and minimize risk of complications. Here we report a 24-year-old postpartum woman with painful edema on her left lower limb diagnosed as having left leg DVT. After a detailed investigation, she was diagnosed as having MTS, a rare cause of DVT. The patient underwent pharmacomechanical treatment with ultrasound-enhanced thrombolysis: EKOS EndoWave Infusion Catheter System (EKOS), inferior vena cava filter placement, and balloon angioplasty. She was discharged with coumadin prescription. In a case of left lower limb DVT, particularly in the younger age group, further investigation using computed tomography angiography should be performed, and MTS should be considered as a differential diagnosis for mortality and morbidity.