50 patients with knee osteoarthritis scheduled for a unilateral total knee arthroplasty were randomized to receive navigation-assisted or conventional prosthesis alignment. Outcomes of interest included alignment angles (mechanical axis, frontal femoral angle, frontal tibial angle, sagittal femoral angle, sagittal tibial angle, femoral component rotation), revision rate, and functional outcomes (WOMAC score, modified Knee Society Score knee and functional sub-scores). Follow up was performed up to 4 years post-operation. No cases of revision were reported in either group. Frontal tibial angle, mechanical axis alignment, and femoral component rotation were significantly in favour of the navigation-assisted group compared to the conventional group. No differences in remaining alignment angles or functional outcomes were observed between the two groups.