The clinical and pathological features of 15 infants with malignant rhabdoid tumors of kidney are presented. These tumors were identified among 391 primary renal neoplasms in this hospital. The male/female ratio was 2.8:1.0, mean age at diagnosis was 18 months with a range from 4 to 55 months. Of the 10 patients with follow-up records, 8 have died, 2 were alive and free of disease 15 and 55 months after the diagnosis respectively. A wide histologic spectrum was encountered. All tumors exhibited classical morphology in at least some areas, characterized by solid proliferation of monotonous tumor cells with vesicular nuclei and prominent nucleoli, abundant cytoplasm and intracytoplasmic inclusions. Immunohistochemical studies were performed in all 15 cases. Vimentin was positive in all tumors, ENA in 12, cytokeratin in 8, desmin in 2 and myoglobin in one. All cases were negative for presence of lysozyme, NSE and neurofilament. Our results show that this tumor is a distinctive and highly malignant neoplasm of the infant kidney with considerable morphological and immunohistochemical diverse phenotypes.