The clinical and pathological variables are important factors that may be associated with tumor progression and consequently, the prognoses of the disease. The glutathione S-Transferases GSTM1, GSTT1 and GSTP1 are enzymes from the second phase II of biotransformation that work in the detoxificatin pathways of a wide range of exogen agents including the carcinogens. The GSTM1, GSTT1 and GSTP1 genes are polymorphic in humans and their variants have been related in some populations an increased neoplasia risks, including colorectal cancer. In this retrospective study 50 biopsies of patients with colorectal carcinoma of South Brazilian were analyzed polymorphisms in the genes GSTM1, GSTT1 and GSTP1 by Multiplex PCR and RFLP for the clinical and pathological variables: location, stage and differentiation. There were no significant p values for the variables: stage (p=0,28, p=0,93 e p=0,67), differentiation (p=0,70 e p=0,37)and location (p= 0,23. p= 0,58 e p= 0,60 )respectively and the presence of polymorphism of GSTM1, GSTT1 and GSTP1 in variables staging and location. The only clinicopathological variable that showed significant value in the differentiation of CCR was the polymorphism GSTP1 ile/val and val/val (p= 0,046), however, more research is needed to confirm these findings, since these results may have been influenced by the reduced number of biopsies analyzed.