Fibreoptic bronchoscopic cytodiagnosis by washings and brushings and histodiagnosis by forceps biopsy were studied in 484 Chinese patients with bronchial carcinoma. When the tumour was bronchoscopically visible, the yields of the three procedures were: washings 76%, brushings 74% and biopsy 82%, giving a total yield of 94%. For peripheral bronchoscopically non-visible tumour, the yields were 52%, 52% and 61% respectively, making a total yield of 86%. Bronchial washings and brushings were important complementary procedures to biopsy and provided the exclusive diagnosis in 12% of the central and 25% of the peripheral tumours. The cytologic cell typing accuracy is 92% for epidermoid carcinoma, 87% for small cell carcinoma, 83% for adenocarcinoma and only 38% for large cell carcinoma. The accuracy of cell-typing of the two bronchial cytodiagnostic methods was comparable in central tumours, but higher with brushings in peripheral tumours.