Many ventilated trauma patients thought to have nosocomial pneumonia have pulmonary contusion or systemic inflammatory response syndrome with tracheobronchial colonization. Fiberoptic bronchoscopy with quantitative culture techniques of protected specimen brush (PSB; threshold 10(3) cfu/mL) or bronchoalveolar lavage (BAL; threshold 10(5) cfu/mL) can potentially eliminate the false positive cultures of the upper airway seen with routine sputum aspirates (RS). However, bronchoscopy is expensive, and routine use may not be cost effective. This prospective study evaluated the patient charges associated with bronchoscopy and quantitative cultures compared with RS for the diagnosis of nosocomial pneumonia. Specimens were obtained by RS, PSB, and BAL from the lower airway in 107 trauma patients (136 sets of triplicate cultures). All patients had clinical evidence suggestive of pneumonia (fever, leukocytosis, purulent sputum, abnormal roentgenographic findings). Typical oral flora were considered contaminants; no gram-negative specimens were excluded. Mean age was 40 years and mean ISS was 29. Seventy-eight percent had blunt injuries, 22% penetrating, and 42% had chest injuries. The incidence of nosocomial pneumonia according to each method was: RS-73%; PSB-34%; BAL-25%. Considering all charges involved (bronchoscopy, equipment, microbiologic analysis, and antibiotics), and based on a 14-day course of ceftazidime and vancomycin, the charges for PSB were 58% of RS, and charges for BAL were 43% of RS. We conclude that the charges associated with bronchoscopy are high, but can be offset by antibiotic savings. Side effects of unnecessary antibiotic therapy would be avoided. Further study is needed to determine the efficacy of PSB or BAL in trauma patients.