Spontaneous Large Renal Pelvis Haematoma in Ureteropelvic Junction Obstruction: A Rare Case Report Spontaneous renal haemorrhage is a rare occurrence with potentially serious consequences. This presented case was an even rarer form of ureteropelvic obstruction (UPJO), which was spontaneous bleeding into the renal pelvis in a patient who was not previously investigated for UPJO. We presented a 17-year-old gentleman who presented with lower abdominal pain for one week and painless haematuria for two days. Initial computed tomography angiography (CTA) renal revealed haematoma with a grossly dilated pelvicalyceal system. The patient was initially treated conservatively. However, in the ward, he suddenly developed severe left-sided back pain, decreased haemoglobin level and persistent gross haematuria. Repeated CTA renal revealed worsening left renal haematoma with a grossly dilated pelvicalyceal system, and he was panned for nephrectomy. A review of the literature followed with a discussion of the case were done in this study.