Summary
Background: Idiopathic spontaneous retroperitoneal haematoma is a rare clinical entity with acute onset ofabdominal pain and presenting as acute abdomen. It presents a diagnostic and management dilemma and hence a thorough evaluation is required in handling this condition. There are various aetiological factors for retroperitoneal haematoma but in some small number of cases, the causative factor may never be found. Imaging is the goal standard in diagnosis and follow up of the patient.
Case Report: I report a case of a previously fit 24-year-old man with absolutely no history of trauma with idiopathic spontaneous retroperitoneal haematoma. Various investigations revealed no obvious aetiology and it resolved on conservative measures.
Conclusions: Idiopathic spontaneous retroperitoneal haematoma usually pose a diagnostic dilemma. Conservative approach to treatment is recommended especially where no definite cause has been identified.

Keywords: haematoma, spontaneous, idiopathic, Retroperitoneal Space, acute abdomen