Renal haematomas are uncommon pathologic entity. The most frequent cause of perinephric haemorrhage is trau¬ma: however differentiation between a simple haematoma and haemorrhage associated with an underling benign or malignant lesions must always be considered. Spontaneous renal bleeding are caused by renal tumors in 60% of cases. The post-traumatic haemorrhage can lead. in many cases. to perforili diagnostic imaging exams that will show renal tumors still asymptomatic. Vie present a case of a 31 year old man. with negative remote pathologic anamnesis. come to our observation for a slight sports trauma causing a piercing pain in thè left lumbar region and an important anaemia. After diagnostic exams supposing thè presence of a renal tumor, surgical treatment was performed. The surgical exploration showed a neoplasia hard in texture largely in place of the normal renal parenchyma. The histological examination of the kidney revealed a clear cell renal carcinoma, Fuhrman II grade. The analysis of the literature shows that renal haemorrhages are often linked to renal tumors. The incidental discovery of renal tumours gives a supplementary benefit to patients in terms of survival and should be considered as a prognostic factor in additing to stage and grade. Renal tumors have often a negative prognosis because they gel symptomatic too late. So to obtain a diagnosis as earlier as possible it is essential to get the greatest benefit from the surgical treatment.