Xanthogranulomatous pyelonephritis (XGP) is an uncommon and aggressive form of inflammation of the renal parenchyma particularly resulting in diffuse renal destruction. A previously healthy 25-year-old woman was admitted to our clinic with right fl ank pain of sudden onset, nausea and high fever. Computed tomography revealed a mass (12 x 7 cm in diameter) around the right kidney with extension to pelvis and paravertebral space. Flank incision was made urgently and a very large perirenal haematoma and abscess formation were found caused by the rupture located at the posterior side of the right kidney. A right nephrectomy was performed and abscess material was evacuated from the perirenal area. XGP was diagnosed by histopathologic examination of the resected kidney. Although XGP regularly demonstrates a gradual progression and presents with nonspecific symptoms, the situation may appear with complications as in our case. Our patient presented with renal rupture and perirenal abscess extending to the pelvis and paravertebral space. To the best of our knowledge, this is the first report of XGP presenting with spontaneous renal rupture in the English literature.