This review considers the literature on bronchoalveolar lavage in the diagnosis of interstitial lung disease published during the last 12 months with the aim of clarifying the role bronchoalveolar lavage can have in diagnostic work-up on the basis of current knowledge and expert opinion. Recent research findings with possible future clinical applications are presented. Various information, useful for research and clinical applications, can be obtained from performing bronchoalveolar lavage in patients with interstitial lung diseases. Indeed, evaluation of cell pattern associated with cell phenotype is used widely in clinical practice to distinguish the various forms and may be of diagnostic value in some interstitial lung diseases, as already known, when the clinical picture is compatible. Bronchoalveolar lavage may also be complementary to high-resolution CT or at least useful for diagnosis by exclusion. A major advance in the last year is recognition of a role for bronchoalveolar lavage in the diagnostic workup of idiopathic interstitial pneumonias, albeit as an auxiliary procedure. It may be useful to exclude infections and tumors, may help to decide whether to do surgical biopsy, and may aid in distinguishing different forms of interstitial lung disease. Although it is not diagnostic for idiopathic interstitial pneumonias, in the presence of cell patterns considered "typical" of the various forms, it can support clinical diagnosis in the absence of biopsy. Because further studies following standardized protocols and guidelines will presumably find new parameters for bronchoalveolar lavage in the diagnostics of interstitial lung diseases, it would be a mistake to consider bronchoalveolar lavage an obsolete tool.