Teratoid Wilms' tumor is a rare renal tumor. Fourteen cases have been reported. A 14-month-old girl was presented to us. She had a right renal mass which was diagnosed as a Wilms' tumor in another hospital. She had been treated with chemotherapy but failed to respond to it. The nephrectomy specimen revealed an encapsulated mass of which the cut surface was solid, firm, gray to yellow tan. Microscopically, the stromal elements were predominant, especially comparing with few blastemal element, but the degree of heterologous differentiation was sufficient to warrant the diagnosis of teratoid Wilms' tumor.