Since data are unavailable on the role of transbronchial lung biopsy (TBB) in pediatric and adolescent patients, we reviewed our two-year experience in 12 patients (median age, 14.5 years). In all 12, the indication for TBB was a persistently abnormal chest roentgenogram (nine with multilobar infiltrates, two with unilateral infiltrates, and one with a cavitary lesion). Overall, a specific diagnosis was made by TBB in six patients, including three patients with sarcoidosis, one with lymphoma, and two with eosinophilic granuloma. In three additional patients, nonspecific histologic findings on TBB combined with clinical findings, roentgenographic patterns, and supplemental laboratory data helped support a diagnosis. Although the need for general anesthesia and the small size of the biopsy specimens may limit the usefulness of TBB in most pediatric patients, TBB may be a useful alternative in carefully selected patients.