200 patients scheduled for total knee arthroplasty were randomized to initial femoral nerve block with or without the addition of dexamethasone (8mg). In both groups, the continuous perineural infusion was used for 72 hours postoperatively. The purpose of this study was to determine if the addition of dexamethasone was met with a significantly prolonged sensory block and reduced morphine consumption over the first 24 hours. Pain scores and incidences of nausea and vomiting were also assessed. Results demonstrated that the use of dexamethasone in femoral nerve block was associated with a significant, 7-hour increase in the duration of the sensory block when compared to those who received bupivacaine with saline. Nonetheless, 24-hour morphine consumption was not significantly reduced in the dexamethasone group compared to the control group.