In the last years an increasing number of subjects experienced respiratory failure and underwent tracheostomy. The aim of the present study was to analyze tracheal aspirates from the inflammatory point of view. Samples were collected from 38 consecutive tracheostomized patients: 13 COPD, 6 with neurologic disorders and 19 with other different causes of respiratory failure. We analyzed cells and soluble mediators related to inflammation and/or infection. We also compared results obtained in the tracheal aspirate of COPD patients with the same determination in the sputum of another group of non-tracheostomized COPD patients (n=41). Regardless of the underlying diagnosis, most of the samples were Pseudomonas aeruginosa positive and cells and soluble mediator did not differ. Treatment with steroids was associated with lower amount of total cells, neutrophils and lymphocytes, whereas treatment with antibiotics was not. Tracheal aspirate neutrophils correlated with PaCO(2) values; neutrophils and eosinophils correlated with their percentages in blood. As compared with sputa obtained from another group of culture-positive non-tracheostomized COPDs, tracheal aspirates showed similar cell count, proportions of inflammatory cells, and infection/inflammatory mediators. In conclusion tracheal aspirates presented high amounts of viable cells and soluble mediators independently to the cause of respiratory failure leading to tracheotomy and they represent suitable specimens to study infection/inflammation interactions.