Introduction. Knee osteoarthritis remains one of the leading causes of disability and a significant reduction in quality of life among older patients. Although total knee arthroplasty (TKA) is considered the gold standard for treating end-stage gonarthrosis, a considerable proportion of patients continue to experience pain and functional limitations after surgery. This has increased interest in preoperative programs designed to enhance rehabilitation potential and optimize treatment outcomes. The aim of the study: to evaluate the impact of manual therapy performed in the preoperative period of total knee arthroplasty on the clinical and functional state of patients after surgery. Materials and methods. A prospective randomized comparative study included 127 patients (75 women, 52 men) with unilateral idiopathic knee osteoarthritis stage III–IV scheduled for primary TKA. Participants were allocated to an experimental group (n=62), which received a course of preoperative manual therapy (three sessions during the month before surgery), or a control group (n=65), which underwent standard preoperative preparation. Assessments were performed using the KOOS (Knee injury and Osteoarthritis Outcome Score), Visual Analogue Scale (VAS) for pain, International Classification of Functioning, Disability and Health (ICF), and goniometry of the knee joint at five time points (from one month before surgery to three months postoperatively). Results. Both groups showed significant improvements in all measured parameters (p