Background: To investigate the knowledge, attitude, and practice (KAP) in patients with knee osteoarthritis (OA) towards perioperative functional exercise after total knee arthroplasty (TKA). Methods: The cross-sectional survey enrolled knee OA patients in two tertiary public hospitals at Shandong Province between September 2023 and January 2024. Demographic characteristics, KAP scores, and Tampa Scale for Kinesiophobia (TSK) scores were gathered via a self-made questionnaires. Results: A total of 583 valid questionnaires were collected, 65.01% were females and 48.89% over 65. The average scores of knowledge, attitude, practice and TSK were 11.17 +/- 4.31 (possible range: 0-16), 21.78 +/- 2.57 (possible range: 6-30), 35.44 +/- 5.80 (possible range: 9-45), and 39.21 +/- 10.75 (possible range: 17-68), respectively. Spearman correlation analysis showed positive correlation between knowledge and attitude (r = 0.3406, p < 0.001), attitude and practice (r = 0.3464, p < 0.001), attitude and practice (r = 0.6390, p < 0.001), negative correlation between TSK and knowledge (r = -0.3663, p < 0.001), attitude (r = -0.2937, p < 0.001), and practice (r = -0.3970, p < 0.001), respectively. Path analysis found that attitude, underlying diseases, occupation, total knee arthroplasty had direct effects on practice. Knowledge, age, education level, residence, diagnosis time, marital status had indirect effects on practice. Total knee arthroplasty had direct and indirect effects on practice (all p < 0.05). Conclusions: While most patients held a positive attitude and practice, concerns and misconceptions regarding perioperative exercises emerged as urgent issues. It is imperative to implement targeted interventions to enhance adherence by addressing factors influencing KAP.