Cell components in the peripheral lung area were examined in 24 asthmatic subjects by bronchoalveolar lavage (BAL) and transbronchoscopic lung biopsy (TBLB). In cases with increased percentage of lymphocytes in bronchoalveolar lavage fluid (BALF), the infiltration of eosinophils and mononuclear cells in the peripheral lung tissue was observed with a high frequency. The increased percentage of eosinophils in BALF correlated with the infiltration of eosinophils and neutrophils in the bronchiolo-alveolar region. A reverse correlation was observed between the macrophage count in the alveolar region and the percentage of eosinophils and lymphocytes in BALF. No significant correlation was present between the percentage of neutrophils in BALF and the infiltration of any type of cell in the lung tissue.