This study was carried out to evaluate the diagnostic yield and safety of flexible transbronchial needle aspiration (TBNA), endobronchial biopsy (EBB) and transbronchial lung biopsy (TBLB) combinations in stages I-III sarcoidosis (SA). Between 1989 and 1997, 74 patients suspected of having SA underwent fibreoptic bronchoscopy along with TBNA + EBB + TBLB or EBB + TBLB. During the same fibreoptic bronchoscopy, TBNA (using a 19-gauge histological needle and contrast-enhanced computed tomography (CT) guidance), EBB (from abnormal or normal bronchial mucosa) and TBLB were performed in stages I (n = 33) and II (n = 25), and EBB and TBLB in stage III (n = 16). The diagnosis of SA required the presence of noncaseating granulomas and the absence of "allergic granulomatosis and angiitis with eosinophilic infiltration" or foreign body reaction, with negative Ziehl-Neelson and methenamine silver stains, as well as negative cultures for acid-fast bacilli, fungi and other organisms. TBNA was diagnostic in 20 (61%) and 10 (42%) cases of stages I and II, whereas EBB was diagnostic in 15 (45%), 12 (50%) and seven (58%) cases, of stages I, II and III, respectively, and TBLB in 17 (52%), 15 (63%) and 10 (83%). By means of TBNA, EBB and TBLB alone, the diagnostic yields were nine (27%), four (12%) and six (18%) cases in stage I, two (8%), four (17%) and seven (29%) in stage II, and two (17%) and five (42%) by EBB and TBLB in stage III, respectively. The diagnostic yield of TBNA + EBB + TBLB was 30 (91%) in stage I and 21 (88%) in stage II, and that of EBB + TBLB was 12 (100%) in stage III. Overall, 63 (91%) cases of SA were diagnosed by TBNA + EBB + TBLB and EBB + TBLB. In six of the eleven bronchoscopically-negative cases, mediastinoscopy (four) or thoracotomy (two) established the diagnosis of SA, whereas the remaining five were diagnosed along with non-sarcoidosis diseases (one case in stage II and four in stage III) by various tissue biopsies in the follow-up. The combination of TBNA + EBB + TBLB and EBB + TBLB provided an overall sensitivity and accuracy of 90% and a specificity of 100%. All six (9%) significant complications--pneumothorax (four) and 40-100 mL haemorrhage (two)--were attributable to TBLB. It is, therefore, inferred that the combination of transbronchial needle aspiration, endobronchial biopsy and transbronchial lung biopsy in stages I and II, and that of endobronchial biopsy and transbronchial lung biopsy in stage III, is safe and cost-effective as well as increasing the diagnostic yield, and should therefore be performed routinely in the diagnosis of sarcoidosis.