The pathology of the pulmonary manifestations of rheumatoid diseases is characterized by its histologic heterogeneity and overlap with other pulmonary diseases. All anatomic compartments are vulnerable; thus, the morphologic changes vary according to the predominant region involved. Furthermore, the histologic patterns of injury are not unique to rheumatic diseases, given their resemblance to those seen in idiopathic forms, or in lung disease associated with other conditions. The patterns of interstitial lung disease, airway disorders, pleural processes, and vascular manifestations are described. The histopathology of selected entities, including the main vasculitides affecting the lung, and Ig G4–related disease are discussed.