Acute obstructive pyelonephritis is a condition with a high risk of complications and may require admission to the intensive care unit. Most of the available data on this condition comes from small, retrospective, single-centre series. To date, no large-scale study has examined the factors associated with the prognosis of patients admitted to intensive care for acute obstructive pyelonephritis. The aim of this study is to describe the population and prognosis of patients admitted to the intensive care unit for the management of acute obstructive pyelonephritis, and to identify factors associated with a poor prognosis in these patients.