Superior vena cava (SVC) syndrome is typically dramatic. Although the diagnosis is usually easy, elucidation of the etiology is difficult. We present a patient who developed SVC syndrome early after transvenous pacemaker implantation and who was subsequently diagnosed with lung carcinoma. The pathogenesis seems to be explained by a combination of two etiologies: lung carcinoma plus transvenous pacemaker implantation. We emphasize that common etiologies such as malignancy should be considered first when faced with SVC syndrome. (C) 2018 Published by Elsevier Espana, S.L.U. on behalf of Sociedade Portuguesa de Cardiologia.