Local anesthesia infiltration has been established as a preferred method of perioperative analgesia in many cosmetic operations. In an attempt to maximize the risk-benefit ratio of local anesthesia, a study was conducted to compare efficacy of two local anaesthetic agents. Bupivacaine was compared to ropivacaine in a bilaterally symmetrical breast surgery model. A local anaesthetic solution containing either bupivacaine or ropivacaine was infiltrated into each of the breasts of 15 patients undergoing either breast augmentation or breast reduction. Both surgeon and patient were blinded to the nature of local anaesthetic agent injected. Patients were requested to score their pain at 1, 2, 6, and 10 hours after surgery on a visual analog scale. The results were analyzed statistically using a cross-sectional time-series regression model employing the random effects option of the xtreg command from Strata Release 6 statistical software. We found that overall analgesia achieved with bupivacaine and ropivacaine infiltrations was not statistically different. The use of a higher dose of ropivacaine is likely to have removed the clinical advantage noted for the bupivacaine group. There was, however, a statistical and clinical difference in the efficacy of local anaesthetic infiltration of both agents in breast augmentation patients as compared to breast reduction patients, local anaesthetic being less effective in patients who had submuscular breast augmentation than in patients who had breast reduction. In view of these findings, it appears reasonable to recommend the use of ropivacaine in high-dose infiltration breast analgesia, as it is reported to be less cardiotoxic than bupivacaine. Serious attention needs also to be given to the adequacy of field infiltration of local anesthesia in submuscular breast augmentation.