An elderly man presented with hypoxemic respiratory failure and pulmonary hypertension. He was a heavy cigarette smoker and had been treated previously for pleuro-pulmonary tuberculosis. His lung volumes and airway function were normal. High resolution computer tomographic (HRCT) examination revealed combined upper lobe emphysema and lower lobe fibrosis. Routine pulmonary function tests may underestimate the degree of functional impairment in patients with combined emphysema and fibrosis. The HRCT examination however provided valuable information.