Over a three-year period, fibreoptic transbronchial lung biopsy (FTLB) was performed in 28 adult Nigerian patients with chronic infiltrative lung disease after sputum examination, haematological, biochemical and serological tests failed to provide a definite diagnosis. Definitive histological diagnosis was obtained in 11 patients (39.3 per cent) while another seven (25 per cent) had distinct histological abnormalities but no specific diagnosis. Tuberculosis and sarcoidosis were the commonest findings. No patient had haemorrhage of more than 50mls while only one had asymptomatic mild pneumothorax. FTLB is very safe and spares a substantial proportion of patients with chronic diffuse lung infiltrates more invasive and expensive diagnostic procedures. This is especially very relevant in developing countries where there is a shortage of surgeons, theatre space and other relevant facilities.