An 11-year-old Caucasian girl presented with shortness of breath on post-operative day 1 following an uncomplicated left percutaneous nephrolithotripsy with stent placement. The patient noted the sudden onset of shortness of breath and pleuritic chest pain, described as a heavy, left-sided pain that worsened on deep inspiration. She denied any numbness, tingling in her neck or arm, dizziness, nausea, vomiting or association with eating. Nephrostomy tube and Foley catheter were removed on post-operative day 0, and urine output was low over the first post-operative night. The patient had a history of type II cysteinuria and recurrent bilateral cysteine stone formation. She had undergone right-sided percutaneous nephrolithotripsy without complication 3 months prior to presentation. Post-operative medications included cefazolin and morphine. A chest radiograph taken shortly after the lithotripsy showed opacification of the left hemithorax, interpreted by Radiology as being consistent with left lung atelectasis (Fig. 1a).