Thromboembolic complications are among the most important extrarenal consequences of nephrotic syndrome (NS). In addition to deep vein thrombosis in the legs and pulmonary embolism, NS is very frequently accompanied by renal vein thrombosis. Due to enhanced procoagulatory and antifibrinolytic potential and reduced anticoagulatory potential, multifactor disruption of hemostatic equilibrium leads to hypercoagulability in NS patients, which is aggravated by an increase in blood viscosity and endothelial dysfunction. Circulating antibodies against α-enolase, a plasmin(ogen)-binding protein, and the possibility of certain molecules being renally eliminated in specific manner are discussed as reasons for the particular frequency of thromboembolic complications in patients with idiopathic membranous nephropathy. Serum albumin concentration is an indicator for the risk of thrombosis in NS patients. When applying the current KDIGO (Kidney Disease: Improving Global Outcomes) clinical practice guideline for glomerulonephritis to NS patients with a serum albumin concentration of less than 25 g/l and at least one additional thrombogenic risk factor, primary prophylactic anticoagulation (“conditioned prophylaxis”) with an orally administered vitamin K antagonist (target INR 2–3) is recommended as long as the serum albumin concentration is less than 30 g/l.