An inflammatory response has been observed in lung cancer both locally and systemically. The aim of the present study was to investigate whether the alveolar compartment was involved in the inflammatory response in non-small cell lung carcinoma (NSCLC). Both inflammatory mediators in bronchoalveolar lavage fluid (BALF) and cytokines produced by alveolar macrophages (AM) were investigated. Twenty patients with newly detected NSCLC and nine control subjects were studied. The patients had not been treated with chemotherapy, radiotherapy or with systemic or inhaled corticosteroids. All patients and control subjects were current smokers or stopped smoking recently. BAL was performed in the affected lung as well as in the contralateral lung of NSCLC patients, and only unilaterally in control subjects. Comparable results were demonstrated for the levels of the of the inflammatory mediators TNF-a, Interleukin (IL)-6, IL-8, both soluble TNF receptors and the soluble adhesion molecules E-selectin and intercellular adhesion molecule (ICAM)-1 between the affected lung and the contralateral lung in the NSCLC population as well as between the NSCLC population and the control subjects. Moreover, no significant differences in cytokine profiles of AM were found between AM obtained from the affected lung and from the contralateral lung. Although BAL is a useful tool in the diagnostic procedure for NSCLC, the present findings suggest that BAL does not reflect the enhanced inflammatory state, as reported in plasma and in the interstitial compartment around the tumour cells in NSCLC.