The superior vena cava (SVC) syndrome is a clinical entity caused by obstruction of the superior vena cava by infiltration, compression or thrombosis. Cancer is the most common underlying cause of superior vena cava obstruction. The incidence of catheter-induced superior vena cava obstruction is rapidly increasing. Fibrosing mediastinitis and Behçet disease are rare causes of SVC syndrome. Clinical presentation of SVC syndrome may include cough, dyspnea, dysphagia, and swelling or discoloration of the neck, face and upper extremities. Aim of this study is to evaluate the role of Multislice CT in study of superior vena cava obstruction syndromes and assessment of collateral circulation in different causes of superior vena caval obstruction.