Erdheim-Chester disease (ECD) is a rare systemic histiocytosis with urologic manifestations in a majority of affected patients. An important manifestation is a pronounced retroperitoneal fibrosis with reported dense inflammatory rind surrounding the kidneys. We report a case of a patient with large stone burden necessitating percutaneous nephrolithotomy and the implications related to his Erdheim-Chester-related retroperitoneal fibrotic changes. Foreknowledge of these implications may inform perioperative counseling and surgical planning to maximize opportunity for successful outcomes.