Many researchers have begun to examine the potential role of preoperative intervention, as a means of improving patient outcomes after arthroplasty. The aim of the study was to examine the effect of a 4-week pre-operative physiotherapy programme in patients with osteoarthritis undergoing total knee arthroplasty (TKA). Thirty-two patients scheduled for primary TKA were randomized in study and control groups. Participants completed a series of baseline questionnaires (WOMAC, SF-36 and KOOS) and functional testing (isometric quadriceps strength assessment, 20 meters flat surface walk test, and chair 30s Chair Stand test). The participants, in the study group, exercised 5 times per week for 4 weeks before TKA. Both groups were evaluated six weeks (P0) and one week before (PI) arthroplasty. Post-intervention assessment occurred at 4 (P2) and 12 (P3) weeks after surgery. Both groups took part in the same inpatient rehabilitation program after surgery. The results showed a statistically significant difference in isometric strength of the quadriceps between two groups in the PI and P2 assessment (p <0.05), but not in P3 (p = 0.708). The intervention group showed significant improvement in SF-36 score in PI and P2 evaluation (p <0.05). Also preoperatively observed and improvement in the WOMAC scores (p <0.001), KOOS (p = 0.022) and in the chair stand test (p = 0.021). Contrary, similar findings were found for the walking velocity between two groups (p>0.05). Although preoperative intervention showed clinically significant improvement in the strength of the quadriceps and mental health immediately before and 4 weeks after TKR, does