76 patients scheduled for shoulder arthroplasty were randomized to postoperative analgesia with either a continuous or single-shot interscalene block. Patients were assessed for pain, opioid consumption, the length of stay, and the incidence of adverse events. In addition, patients who were administered continuous infusion were monitored for rate of catheter withdrawal. Results demonstrated significantly lower pain scores on the first postoperative day in the continuous group compared to the single-shot group, but no significant differences at other time points. Opioid consumption was also significantly lower in the continuous group compared to the single-shot group. There were no significant differences between groups for the length of stay or adverse events.