Light chain deposition disease (LCDD) is a rare condition characterized by extracellular light chain deposition in tissues. Patients commonly have an underlying plasma cell dyscrasia, and produce excess levels of monoclonal light chains. Renal involvement is the most common clinical manifestation. Rarely, light chains are deposited in the lung. We present the pathologic and radiographic findings of three patients with biopsy-proven pulmonary light chain disease and a review of the literature.