Objective? To investigate the occurrence and influencing factors of falls in elderly patients with knee osteoarthritis (KOA), and provide scientific reference for the prevention of falls in elderly patients with KOA. Methods? Using convenience sampling method, 104 elderly patients diagnosed as KOA in orthopaedic wards of four ClassⅢ Grade A hospitals in Hangzhou from November 2017 to August 2018 were selected as subjects. General Information Questionnaire, Morse Fall Scale(MFS)and the Barthel Index(BI)for Activities of Daily Living (ADL) were applied in the investigation. Single factor analysis and multiple factor Logistic regression were used to analyze the influencing factors of falls in elderly KOA patients. Results? A total of 104 questionnaires were sent out in this study, and 95 valid questionnaires were recovered, yielding an effective recovery rate of 91.35%. The incidence of falls in elderly KOA patients was 45.26% (43/95), of which 62.79% (27/43) had fallen twice or more. There were significant differences in knee injury history, staircase climbing and falls among elderly KOA patients (P＜ 0.05). There were significant differences in the risk of falls between elderly KOA patients in "whether taking drugs", "whether using walking aids", "status of self-care ability", and "age" (P＜ 0.05). Logistic regression analysis showed that history of knee injury, frequent staircase climbing and use of walking aids were the influencing factors of falls in elderly KOA patients (OR=4.028, 25.569, 3.191; P＜ 0.05). Conclusions? In view of the influencing factors of falls in elderly KOA patients, individualized nursing measures should be taken to strengthen falls risk assessment, carry out fall prevention related education and improve patients' social support, which will help to reduce the incidence of falls and further improve patients' quality of life.