The present investigation evaluated the changes of cytologic: constituents m bronchoalveolar lavage (BAL) fluid and to delect utility for diagnosis ol respirator/ disease in calves. For this purpose, 18 calves with acute respiratory disease. 17 calves with chronic respiratory disease and 11 healthy oalvos were used as materials. All calves were examined with regard to clinical examination, complete blood cell counts and BAL fluid analysis. BAL fluid was investigated cytologically. biochemically and bacteriologically. BAL fluid lactate dehydrogenase (LDH), alkaline phosphatase (ALP) aclivities and total protein (TP) concenlrations wero significantly higher (p< 0.01) in the calves with acute and chronic respiratory infection compared to the normal calves. BAL fluid neutrophil percentages were significantly higher (p< 0.01) in Ihe calves with acute and chronic respiratory infection compared lo Ihe normal calves. Macrophage percenlages in BAL fluid were significantly decreased in the calves with acule and chronic respiratory infection. In the same time, BAL fluid macrophage percentage was significantly higher in the calves with chronic respiratory infeclion compared lo that of the calves with acute respiratory infection. The results of this study showed thai, translracheal BAL fluid analysis was a fast, safe, simple technique producing rapid diagnosis in pneumonic calves. The diagnostic potontial of the percentage ol alveolar macrophage and neutrophil counts in BAL lluıd were validated, Cytologic examination of the respiratory tract may provide a etiopathologic diagnosis or information for improved case management, until more complex diagnostic procedures are performed.