Whereas renal biopsy is routinely performed in nephrology for the management of renal failure or follow-up of kidney grafts, it has historically been seldom used in urology for the work-up of kidney tumours because of its low yield. Since a few years however, some authors recommend to biopsy select renal lesions to improve their diagnosis and management. Indeed, biopsy technique has evolved, leading to better tissue sampling. Moreover, the risk of tumoral seeding of the needle tract has proven to be negligeable. Renal biopsy appears now to be useful for managing atypical solid renal lesions, those < or =3 cm, possible neoplastic lesions in solitary kidneys, bilateral renal tumours, putative renal metastasis, so as lesions in functionally deficient kidneys.