To determine whether viral infections are related to renal cell carcinoma (RCC), we studied 49 patients with RCC (29 patients were males with age ranging from 30 to 81 years and a mean of 57.5 years; 20 patients were females with age ranging from 36 to 70 years with a mean of 58.4 years) and 16 non-neoplastic kidney patients as controls. Tissues specimens from study patients and controls were examined by nested polymerase chain reaction (PCR) to determine the presence of DNA of several viruses including human papilloma virus (HPV), Epstein-Barr virus (EBV), and polyoma viruses (BKV and JCV). Our results revealed that 7 of 49 (14.29%) RCC tissue specimens had HPV DNA compared with none of 16 non-cancer control subjects. Regarding the HPV types, all the positive results were high-risk HPV types (type 16 in three and 18 in four patients). The present study suggests that HPV infection, especially high-risk types, is associated with RCC. However, more studies are necessary to demonstrate the molecular oncogenic processes involved in this association.