Introduction. Our objective is to report a case of an infrequent entity as the giant hydronephrosis. Case Report. We report the case of an 82-syear-old male referred for a poor general condition. A radiological study revealed a great left hydronephrosis secondary to an urothelial carcinoma. The patient died due to his poor general condition. A histological diagnosis revealed a transitional cell carcinoma of renal pelvis and ureter and atrophic renal parenchyma. Conclusion. Giant hydronephrosis represents a very often entity to be taken into account in cases with big cystic abdominal masses in absence of unilateral or bilateral kidney. Simple nephrectomy is the treatment of choice in most cases. Nevertheless, in cases of nonsubsidiary surgery, percutaneous drainage may be necessary.