Pergolide is an ergot-derived dopamine agonist used in Parkinson's disease and, increasingly, in restless legs syndrome. We report a patient with a 2.5-year history of weight loss, pleuropulmonary fibrosis, and exudative pleural effusion that developed insidiously while taking this medication. The extensive and invasive workup that preceded the diagnosis highlights the difficulty in attributing such a process to a drug reaction. This is the second report of such a reaction to pergolide, which is one of the increasing number of ergot-derived compounds in common clinical use.