In recent years, regional anaesthetic techniques are being preferred as an adjuvant to general anaesthesia for the relief of postoperative pain. Breast surgeries are widely performed for cosmetic as well as oncological reasons and are associated with severe pain, PONV and respiratory complications due to inadequate pain relief. The present study was carried out to compare the efficacy of bupivacaine and ropivacaine in a single injection paravertebral block for controlling the postoperative pain after an elective breast surgeries. Method: Seventy-two female patients scheduled for elective breast surgery were randomized into two groups; R (Ropivacaine group) and B (bupivacaine group), 36 patients were allotted to each group. Both the groups received single injection paravertebral block with either of the drug. Surgery was conducted under general anaesthesia in both the groups. Intensity of postoperative pain was measured by VAS score at 2, 4, 6, 9, 12, 18 and 24 hrs. Intensity of pain and the analgesic consumption over the past 24 hours were recorded. Duration of postoperative analgesia was calculated by the time of first analgesic requirement. Results: VAS scores in the immediate postoperative period that is 2-12 hrs. were comparable between both the groups (p> 0.05), however the VAS score at 9, 18 and 24 hours were significantly higher in group R. Fentanyl consumption in the first 24 hours was 68.06±23.612µg for the group R as compared to 76.39±17.87µg for the group B which is statistically insignificant. The time to request for 1st analgesic was 646.56±115.85min in the group R and 609.25±75.02mins in the group B (p>0.05) which is also statistically insignificant. Conclusion: Ropivacaine and Bupivacaine both provide good quality of analgesia after single injection thoracic paravertebral block in breast surgeries.