139 patients scheduled for unicompartmental knee arthroplasty were randomized to the procedure using either robotic-assistance technology or conventional instrumentation. The purpose of this study was to compare the accuracy of postoperative component alignment, relative to preoperatively planned alignment, between groups. Postoperative CT was performed at 3 months. The robotic-assistance group demonstrated significantly lower median error between pre- and postoperative alignment of femoral and tibial components in the sagittal, coronal, and axial planes when compared to the group which underwent surgery with conventional instrumentation.