Background: The aim of this study was to determine the diagnostic yield of flexible bronchoscopy in endoscopically visible malignancies and to evaluate whether cytological examination, including bronchial washings and brushings, increase the diagnostic yield compared with bronchial biopsy alone. Methods: We reviewed a series of bronchoscopies over a period of 7.5 years in which an endoscopically visible tumour was identified and which had a definite cytological or histological diagnosis of pulmonary malignancy obtained by bronchoscopy or any other examination. Results: The criteria were met by 174 bronchoscopies. In 155 bronchoscopies all specimens including bronchial washings, brushings and biopsies were obtained; the overall diagnostic yield was 88%. This compared with a diagnostic yield of 77% for biopsies only (P < 0.001). The individual diagnostic yields for biopsies, brushings and washings were 77, 50 and 38%, respectively. The overall diagnostic yield of cytology was 61%, providing a diagnosis in 95 patients. Of 11 repeat bronchoscopies after an initial non-diagnostic bronchoscopy, 9 were diagnostic. Conclusion: The tumour detection rate with flexible bronchoscopy in endoscopically visible lung malignancies is high. Cytology-based sampling techniques by means of bronchial washings and brushings significantly increase the overall diagnostic yield compared with forceps biopsy only. Repeat bronchoscopies after an initial non-diagnostic bronchoscopy have a relatively high diagnostic yield and should therefore be considered in all patients with endoscopically visible tumour.