Dyspneic smokers who come to clinical attention demonstrate varying combinations of emphysema, airway inflammation, and fibrosis in addition to the changes of pulmonary Langerhans' cell histiocytosis. There is also growing acceptance of a link between cigarette smoke and alveolar wall fibrosis. Acute eosinophilic pneumonia is a dramatic response to recent-onset smoking seen in a small number of individuals. The interconnected pathways that lead to lung inflammation and fibrosis in cigarette smokers are slowly coming into focus.