Members of the glutathione S-transferase (GST) superfamily exhibit polymorphic expression. GSTs are investigated as biomarkers of risk for various cancers, including renal cell carcinoma (RCC). The aim of this study was to test the association between GSTM1 and GSTT1 polymorphism and susceptibility to RCC, independently or in conjunction with known risk factors. Genomic DNA was isolated from 182 controls and 76 patients with RCC. GSTM1 and GSTT1 genotypes were determined by multiplex PCR. Data obtained were analyzed with respect to RCC risk factors including smoking and occupational exposure. The frequency of GSTM1-null genotype was higher in patients with RCC (60.5%) compared to controls (47.2%). GSTT1-null genotype was found in 28.6% controls and 27.6% of cases. GSTM1-null individuals exhibit 1.9-fold increased risk of RCC (95% CI: 1.06-3.33). The presence of GSTT1 active genotype was associated with increased risk of RCC in occupationally exposed subjects when unexposed GSTT1-null subjects were used as a comparison group (OR: 2.48; 95% CI: 1.05-5.86). No association was found between the inactive form of GSTM1 and GSTT1 and smoking in RCC patients. In a Serbian cohort of patients, the presence of a GSTM1 active genotype is protective against RCC, whereas a GSTT1 active genotype increases RCC risk in occupationally exposed subjects.