This study was carried out in 59 patients with histological evidence of pulmonary sarcoidosis. In all patients, bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB) were performed simultaneously. In histologic specimens of TBB, 24/59 (41%) patients had luminal alveolitis, 36/59 (61%) mural alveolitis, 41/59 (69%) granulomas 11/59 (15%) diffuse fibrosis and 24/59 (41%) focal fibrosis. Cytological examinations of BAL revealed 22/59 (37%) patients without alveolitis, 20/59 (34%) with low intensity alveolitis and 17/59 (29%) with high intensity alveolitis. Comparative analysis of these patients showed the association of the alveolitis in BAL and the mural alveolitis or granulomas in TBB (p less than 0.01). The conclusion of this study is that cytological findings in BAL represent interstitial cells very well.