Tuberous sclerosis complex (TSC) is an autosomal dominant hereditary disease characterized by a high rate of spontaneous mutations involving at least two loci: TSC(1) (9q34) and TSC(2) (16p13). It results in hamartomas or tumours which can affect a variety of organs, most commonly the brain, skin and kidneys. At least half of patients with TSC have underlying renal pathology, most commonly angiomyolipomas (AML) and/or cysts with, more rarely, adenocarcinoma, but oncocytomas, sarcomas, interstitial fibrosis and glomerulosclerosis have all been reported. Renal disorders may be asymptomatic or associated with acute lumbar ache, hematuria, abdominal mass, retroperitoneal hemorrhage. Renal failure is infrequent. The diagnosis of this disease is often performed, as in the present cases, very late and it is made possible by radiological examinations such as TC scan o RMI (when renal failure is present), usually performed after macrohaematuria or abdominal or renal colics or renal failure. When fatty tissue cannot be demonstrated within renal lesion (as in the female case), biopsy can be undertaken to exclude malignancy. Histology at the edge of an AML may look like renal carcinoma, but recent studies suggest that it can be differentiated by staining for HMB-45 which is positive in AML and negative in carcinoma. Two cases of tuberous sclerosis with different neurological fenotype, with bilateral renal angiomyolipomatosis and heavy renal failure, are presented.