Objective To identify the sonographic manifestations of left inferior vena cava variation and analyze the diagnostic value of ultrasound in the diagnosis of the complications caused by the left inferior vena cava.Methods 11 cases with left inferior vena cava variation detected by ultrasound in our hospital between January 1st 2008 and May 30, 2019 were retrospectively reviewed. The sonographic manifestations of left inferior vena cava variation and the related complications were analyzed. Results Of the 11 patients with the left inferior vena cava, “nutcracker phenomenon” was present in 1 case, venous thrombosis in the left iliac vein was detected in 1 case, venous thrombosis in the right iliac vein and the right lower extremity were identified in 2 cases, venous thrombosis in both iliac veins and both lower extremities were found in 1 case. The other 6 cases with the left inferior vena cava did not have related complications. Conclusion The left inferior vena cava does not cause hemodynamic abnormalities in most cases, but identifying the position, course and reflux route of the left inferior vena cava can not only explain the manifestations of various related complications caused by the variation, but also have important significance for thoracic and abdominal surgery.