As-needed (PRN) oral pain medication is an essential part of multimodal pain therapy. Medication delivery is often delayed because of multiple demands upon nursing time in a busy postoperative nursing unit. Postoperative pain control was compared using either the manual delivery of PRN oral pain medication or a bedside oral patient-controlled analgesia device. Thirty patients in each group completed a survey on the day of discharge, and additional data were collected by chart reviews. Device patients had significantly better pain scores than the usual care group on postoperative Day 2 and within the last 24 hours prior to discharge. The device group reported statistically less pain interference overall with general activity, mood, physical therapy, sleep, and appetite. Use of an oral patient-controlled analgesia device may improve pain management and patient function following total knee arthroplasty compared to the traditional delivery of oral PRN pain medication.