Spontaneous rupture of the kidney with perirenal haemorrhage is a rare and serious complication of polyarteritis nodosa (PAN), usually requiring urgent surgery. The present case was a 28-year old male, who had been ill for 14 days, with abdominal pain, loss of appetite, nausea and vomiting. The patient was in shock on hospital admission. Explorative laparotomy revealed a massive haemorrhage from the right kidney. The kidney was removed and histological examination of the specimen revealed polyarteritis nodosa. The clinical history of the presented case is similar to previously described cases of kidney rupture in PAN. In the case presented, however, the diagnosis was first established histologically, while the diagnosis in most of the former cases was established on renal angiography, with findings of spindle-formed renal aneurysms.