Post-Operative Cognitive Dysfunction incidence, after OPCAB, is about 33-50%. Measuring and preventing fall in rSO₂ using NIRS can help reduce this complication. Methods: All patients underwent Cognistat test preoperatively as well as on 7^th post-operative day. Patients in cases group were monitored intra operatively using NIRS for fall in rSO₂ and corrected while those in control group were not. Results: Statistically significant fall in post-operative Cognistat score was found in patients in control group whereas patients in cases group whose rSO₂ fall was promptly corrected scored better in Cognistat test. Conclusion: Using NIRS to measure rSO₂ intra operatively and correct its fall helps in reduction of POCD after OPCAB and preservation of Cognitive ability.