One hundred patients with advanced osteoarthritis were randomized to receive either conventional total knee arthroplasty (TKA) (n=50) or patient-specific instrumentation (PSI) TKA (n=50). The primary outcome of interest was the alignment of the mechanical axis and component positioning. Secondary outcomes included intraoperative parameters (operation time, tourniquet time, estimated blood loss, and length of hospital stay) and functional scores (Knee Society Score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)) as well as range of motion (ROM). Outcomes were assessed for up to two years. Overall, the results of the study revealed no statistically significant differences between the groups in terms of mechanical axis alignment, component positioning, intraoperative parameters, and functional outcomes. The PSI group had a slightly shorter operation time. These findings suggest that PSI TKA provides comparable clinical and radiologic outcomes to conventional TKA with the added benefit of a minor reduction in operation time.