Immunohistochemical analysis of INF-R was performed on 110 renal tumors, 25 peritumoral kidney tissues and 10 lymph node metastases. Pathological material was previously studied and classified according to predominant cell type, stage and grade. A statistical analysis was made in order to determine to what extent the immunoexpression of INF-R differed in relation to the histological variables studied. All peritumoral kidney sections, 89/110 tumors and 9/10 metastases proved positive. Membranous expression was related to clear cell carcinomas. Type I INF-R is expressed in RCC, independent of tumor stage and grade, as well as sex, age and survival. INF-R is widely expressed in RCC in any tumoral type, and its expression is preserved in metastatic disease, which may help to target those patients who could benefit from INF therapy.