Among CRC's %15 of the sporadic cases are associated with MSI and these have hypermethylation of the MLH1 promoter associated with BRAF V600E gene mutation. Familial forms do not show BRAF V600E mutation. Method: We investigated the microsatellite instability (MSI) by immunohistochemical study of MLH1, PMS2, MSH2 and MSH6 together with the BRAF mutation presence and their correlation with standard histopathological parameters in 54 sporadic CRC cases. Results: The age distribution was 25-88 with an average of 67,9. Immunohistochemical expression loss of MLH1, PMS2, MSH2 and MSH6 was seen in 18,5 %, 22,2 %, 7,4 % and 11,1 % of the total 54 cases respectively. MSI was seen in 27,8 % of the cases. The BRAF V600E gene mutation was seen in 18 cases and among these 8 cases (44,4 %) showed MSI, while MSI frequency was 19,4 in non-mutated group. And this was statistically significant (p < 0.05). MSI was found significantly correlated with grade and lymph node number (p<0.05). Conclusion: Our study confirmed that sporadic cases of CRC with MSI are associated with the BRAF V600E gene mutation. MSI is correlated with histologic grade and dissected lymph node number.