Modified Radical Mastectomy is the widely followed treatment for operable breast cancers. Among the methods used to alleviate pain, irrigation of wound with 0.25% Bupivacaine is one of the under-utilized methods with good efficiency compared to other drugs.To evaluate the role of local irrigation of 0.25% bupivacaine in alleviating the post-operative pain. This observational study was conducted among 60 female patients who underwent Modified Radical Mastectomy in a tertiary care teaching hospital between January 2017 and July 2018. Thirty (30) patients were randomly allotted to control group, where the routine post-operative pain management was followed. Another 30 were randomly allotted to study group where, before closure of the wound, a 20G scalp vein set was used along the length of the incision with multiple punctures in it for continuous irrigation with 0.25% Bupivacaine. Post operatively Visual analogue scale was used to measure the pain sensation at every six hours for 24 hours. The adverse effects like pain, hematoma, wound dehiscence, infection was noted on all the post-operative days.Both the groups were similar with respect to basic parameters measured. There was a significant reduction in need for rescue analgesia in the study group. There was a significant difference in mean VAS score between both groups from 6 hour of surgery. Post-operative nausea and vomiting was significantly less in the study group. Irrigation of wound with 0.25% Bupivacaine is found to reduce the pain sensation with minimal side effects without systemic compromise.