Renal cell carcinoma (RCC) as a malignant disease is often complicated by invasion of renal veins and inferior vena cava (IVC). Tumor spread up to the right cardiac chambers and pulmonary embolism (PE) are also diagnosed in some patients. We presents two clinical cases of successful surgical treatment of RCC complicated by thrombosis of inferior vena cava and severe PE. There was two-stage surgical approach in the first patient including thoracic procedure with pulmonary thrombectomy and abdominal surgery with nephrectomy and IVC thrombectomy. PE with tumor masses was verified histologically. The second patient had a giant tumor of the right kidney complicated by thrombosis and invasion of suprarenal IVC wall. Moreover, true thrombosis of infrarenal IVC, bilateral iliofemoral phlebothrombosis and previous PE followed by systemic thrombolysis were diagnosed in this patient. The patient underwent right-sided nephrectomy and resection of suprarenal IVC with thrombus. We did not restore IVC continuity and refused left renal vein reimplantation. This surgical strategy was determined by IVC wall invasion, patent venous collaterals, low confluence of left renal vein with IVC, true thrombosis of infrarenal IVC, both iliac and femoral veins and impossible total thrombectomy from IVC and iliac veins.