A 27 yr old man presented with productive cough, fever and manifestations of superior vena cava syndrome. He was an alcoholic but had been in good health until 3 days prior to admission. The physical examination, the chest radiograph and the results of the sputum culture were compatible with Klebsiella pneumoniae pneumonia of the right upper lobe. The superior vena cava scintigram using technetium-99m showed near total occlusion of the superior vena cava, while sputum cytology, chest computed tomography, and bronchoscopy were all negative for malignant aetiology. Antibiotic therapy brought about slow resolution of the pneumonia and also of the superior vena caval obstruction. The follow-up scintigram showed normalized venous flow of the superior vena cava. To our knowledge, this is the first case of superior vena cava syndrome developed in probable association with Klebsiella pneumoniae pneumonia.