Introduction: Renal cell carcinoma (RCC) is the most common malignant neoplasm of the kidney, and sarcomatoid RCC is an aggressive variant. The prognosis of sarcomatoid RCC is much more aggressive than that of nonsarcomatoid renal cell carcinoma tumors. Sarcomatoid renal cell carcinoma is often incurable, even when patients present with localized disease. In this study, the effects of sarcomatoid differentiation on progression and survival rate were evaluated and discussed in relation to the relevant findings in the literature. Materials and Methods: Between January 1998 and January 2009, a total of 27 patients who underwent radical nephrectomy for renal cell carcinoma were retrospectively evaluated. All patients were evaluated by physical examination, routine hematologic and biochemical analysis, and radiologic studies, including abdominal computed tomography, chest X-ray, renal Doppler ultrasonography, if necessary, and in selected cases, magnetic resonance imaging. Results: The median age of the patients was 59.3 years, and the mean follow-up period was 1.25 years, ranging from 6 months to 4 years. The tumor size ranged from 3.5 cm to 14.0 cm. The stage distribution was pT1 in 2 patients, pT2 in 14 patients, pT3 in 9 patients and pT4 in 2 patients. Histopathological examination of radical nephrectomy material showed sarcomatous differentiation in all patients. All patients had Fuhrman Grade IV tumors. All patients with tumors at stage pT3 and pT4 died. The mean survival rate was 25.9% (n=7) at the end of the follow-up period. Conclusions: The results of this study demonstrate that sarcomatoid RCC is aggressive and that the overall prognosis is very poor with this tumor type. Early diagnosis and radical surgery are the only options available to increase life expectancy for these patients. However, the poor prognosis and short survival times of these patients despite radical surgical approaches should be considered. [J Contemp Med 2011; 1(2.000): 62-66]