['To analyze the number of inappropriate stays generated by patients admitted through a pulmonology department over a 1-year period and to identify the causes and predictors of those stays.', 'A representative sample of hospital stays corresponding to patients admitted by the pulmonology department at Hospital de Valme, Seville, Spain, in 2004 was analyzed retrospectively using the Appropriateness Evaluation Protocol. The review was conducted by 2 physicians who did not belong to the pulmonology department. Multiple linear regression analysis was performed to identify predictors of inappropriate stay.', 'Of the 1166 stays analyzed, 1038 (89%) were judged to be appropriate and 128 (11%) inappropriate. The most common reason for inappropriate stay was the delay in performing diagnostic tests and receiving results (64%). The main justification for appropriate stay was the need for respiratory treatment (59.6%) and parenteral treatment (46.1%). The predictive model generated by multiple linear regression analysis identified the following predictors of inappropriate stay: stay on a ward other than the pulmonology ward, diagnosis on admission, and season of the year.'] Does [ Appropriateness of hospital stay in a pulmonology department ]?