A prospective randomized study was performed to compare the clinical and radiological results of primary total knee arthroplasties (TKAs) using a mini-midvastus approach or a mini-medial parapatellar approach in 134 patients. The mini-midvastus approach was used on 68 patients (group A) and the mini-medial parapatellar approach on 66 patients (group B). All knees were implanted with the same posterior-stabilized prosthesis by the same surgeon (T.-S.T.) with the same set of downsized instruments. Mean follow-up in both groups was 30.5 months (range, 24-48 months). Patients in group A achieved an active straight-leg raise and 90° of flexion significantly earlier (P=.017 and P=.025, respectively). However, no significant difference was detected between the groups with respect to range of movement and Knee Society scores at all the postoperative visits and at final follow-up (all, P>.05). In contrast, the tourniquet time was significantly longer in group A (P=.015), with a higher incidence of medialized tibial component (P=.031). We believe that the early clinical results are similar between the mini-midvastus and mini-medial parapatellar approach. The mini-medial parapatellar approach is easier to initially apply and provides better visualization for TKA.