Penetrating lesions of the kidney are less frequent than closed wounds. However, their incidence has increased these past decades, in relation with the augmentation of urban violence. The main causes of penetrating wounds are knives and firearms, with a related rate of renal lesions more important in the second case. The treatment of renal traumas has evolved these past years. Previously, surgical investigations were systematically indicated in most cases, which was associated with an elevated number of nephrectomies. Today, the development of new diagnostic imaging techniques available in most emergency units allows in certain cases the replacement of therapy by a strict follow-up of the patient, the objective being to preserve the kidney. The principal diagnostic investigation is CT scanning with injection of a contrast product, which is useful to adequately classify renal lesions and to make decision regarding the best first-line therapeutic management. In case of penetrating lesion, the first step is the evaluation of the haemodynamic condition of the patient. In case of haemodynamic instability, immediate surgical investigation is necessary. Conversely, if the patient is stable, CT with delayed imaging must be carried out. For grade I and II renal lesions, therapeutic abstention is recommended. Grade III and IV lesions associated with other intraperitoneal lesions that require emergency laparotomy must be surgically investigated and in these cases, reconstructive surgery or nephrectomy must be considered. Most grade IV lesions associated with a lesion of the renal hilus and grade V lesions must be referred to surgery. Minor renal lesions may not be treated; such cases necessitate a follow-up of the patient that should include successive assessments of the haemoglobin and the haematocrite, together with CT and ultrasonographic investigations aimed at the follow-up of lesion evolution and detection of potential urinomas or prolonged bleedings. The progressive decrease of the haematocrite and arteriovenous fistulae must be treated first by an embolization. Untreated patients with persistent urinary fistulae will undergo, if necessary, ureteral catheterization and percutaneous drainage of the urinoma.