We reviewed our experience with terminal stage infections in patients with lung cancer over an 11 year period at Kurume University Hospital. In patients with end-stage lung cancer, the infection is common and a mortal disease. We examined the clinical features and significance of pathogenic microbes isolated from sputum and blood in patients with lung cancer during their last month. Bacteriological examinations from blood done frequently in patients with episodes of fever revealed that bacteremia was one of the most important disease in terminal stage infection. In the blood cultures from the 22 patients various species of pathogenic microbes were recovered, and nine of which were fungi; five Candida albicans, three Candida tropicalis and one Candida parapsilosis. The major species of bacteria isolated from sputum were Staphylococcus aureus, including methicillin-resistant strain, and Gram-negative bacilli; P. aeruginasa, A. calcoaceticus, K. pneumoniae and E. cloacae, which are known to be frequently involved in hospital-acquired infections. However, S. pneumoniae and H. influenzae which were well known to be microbes of respiratory infections were rare. We concluded that we had to reveal the feature of terminal stage infection in order to reduce the fee for medical treatment and improve the QOL of patients with terminal stage lung cancer.