A syndrome including upper-lobe emphysema and pulmonary fibrosis of the lower lungs was recently characterized. It is found most often in men who are smokers or ex-smokers of more than 40 pack-years; their mean age is 65 years. Exertional dyspnea is always present. There are basal crackles. The disease has no known cause; the only certain risk factor is smoking. Pulmonary function tests show respiratory volumes and flows that are often normal or subnormal, while carbon monoxide transfer is substantially reduced and exercise hypoxemia is present. Diagnosis is based on findings from millimeter-slices of computed tomography of the chest, which show either centrilobular emphysema or upper-zone bullous emphysema, associated in 90% of cases with very suggestive paraseptal emphysema and diffuse infiltrating fibrosing lung disease at the bases (subpleural reticular opacities, honeycomb images, traction bronchiectasis), with more frequent ground glass opacities than in idiopathic pulmonary fibrosis. Pulmonary hypertension is present in almost half of all patients and represents the principal negative prognostic factor for this condition, which has a median survival of 6 years.