Objective: To investigate the causes for the misdiagnosis of nonthrombotic iliac venous compression syndrome (NIVCS) and the efficacy of endovascular therapy for this disease. Methods: The clinical data of 23 misdiagnosed cases of NIVCS from January 2011 to December 2014 were retrospectively analyzed. Results: All the 23 patients were female with an average age of 50.3 (36–64) years. All cases were initially diagnosed as primary varicose veins of left lower extremity and underwent high ligation combined with saphenous trunk stripping plus tributary stab avulsion. The patients had recurrence of varicose vein and pain, swelling or fatigue in the affected leg 6.2 (1–13) months on average after surgery. Then, they were diagnosed as NIVCS by prograde venography of the left lower extremity and were treated with balloon dilatation and stent implantation of the left iliac vein. The symptom score (4.2 vs. 6.9) and pressure difference between the two ends of stent (1.70 cmH2O vs. 5.19 cmH2O) were significantly decreased compared with the pre-treatment values (both P<0.05). Assessment for the effects of endovascular treatment was cure in 7 cases and improvement in 16 cases, respectively. Follow-up was conducted for one month to 24 months and no recurrence or stent-related complications occurred. Conclusion: NIVCS has high misdiagnostic rate, so vigilance should be maintained for this disease in female patients with initial symptoms of left limb varicose veins. Endovascular therapy is effective for NIVCS with few long-term complications.