To determine the impact of pulmonary infections on survival in patients with lung cancer, a retrospective review of the records of 121 such patients treated at Howard University Hospital in Washington, DC, was done. There were 77 men and 44 women; 118 were black. The mean age was 63.5 years. Forty-three patients had squamous cell carcinoma, 31 had adenocarcinoma, 18 had large cell carcinoma, 19 had small cell carcinoma, and ten were unclassified. The stages were as follows: two patients in Stage 0, 15 in Stage I, seven in Stage II, 45 in Stage III, and 44 in Stage IV. Eight patients could not be staged at diagnosis. Eighty-five patients (70%) had documented infections; 37 had single episodes; and 48 had more than one. The five most common organisms recovered were alpha/gamma streptococci, Staphylococcus aureus, Klebsiella pneumoniae, Enterobacter aerogenes, and Pseudomonas aeruginosa. The median survival of all infected patients was 4.2 months which was significantly shorter than that of uninfected patients who had a median survival of 12.9 months (P less than 0.05). When Stage III patients were analyzed separately, infected patients lived a median of 5.8 months and uninfected patients, 13.4 months (P less than 0.05). This study indicated that pulmonary infections frequently occur in patients with lung cancer and suggested that they may adversely affect survival.