Objectives: Owing to safety of Modified Pectoralis block and limited studies available our study will compare the analgesic efficacy of Modified Pectoralis block with the combination of local and pocket infiltration after MRM. Design Open label randomized trial. Setting: Indira Gandhi Medical College, Shimla, HP, India. Participants 60 ASA physical status I-II patients (aged 25-65 years), scheduled for elective MRM procedures were recruited for the study. Intervention Group I (PEC 30 patients) received ultrasound guided PEC block preoperatively and Group II (local infiltration 30 patients) received local anaesthetic infiltration at surgical incision and pocket infiltration postoperatively. Patients were induced with standard general anaesthesia and then after reversal and shifted to recovery room. Main Outcome and Measure Post-operative pain assessment was done using Visual Analogue Score at O hour (Time taken as patient is shifted to PACU), 30 min, 1, 2, 4, 6, 12 and 24 hours. Results: In the PACU, the mean for rescue analgesia required in group 1 was 30.07 (SD = 3.473) and in group 2 was 8.13 (SD = 1.196) and this was statistically significant. The difference in mean of VAS score in group 2 at 6 hrs was (3.00) and in group 1 was (1.73) and this score increased significantly in next hours. The mean of total analgesic required in first 24 hrs in group1 was 0.00 (SD = 0.000) and in group 2 was 2.63 (SD = 556). Conclusion: Ultrasound guided PEC block had prolong post-operative analgesia as compare to local anaesthesia infilteration at surgical incision with pocket infilteration post-operatively.