Aim: In this study, we evaluated the presence of sarcopenia multidimensionally in patients with knee osteoarthritis (OA) using clinical, ultrasonographic and biochemical parameters, and in this respect, it was aimed to investigate the relation between OA and sarcopenia and to identify the most practical, easily accessible and inexpensive method for investigating sarcopenia.Materials and methods: 102 patients with clinical and radiological diagnosis of knee osteoarthritis and 33 healthy control subjects were included in the study. The detailed musculoskeletal system examination of the patients included in the study was carried out by a single physician, and blood sample tests were recorded .Dual-X-ray absorptiometry (DEXA) is used to measure Body composition parameters and muscle mass measurements, isometric muscle strength evaluations, handgrip strength and gait speeds for diagnosis of sarcopenia. Short-form -36 (SF-36) The Nutritional Assessment-short form (MNA), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the International Physical Assessment Questionnaire Short Form (IPAQ-SF) and the Center for Epidemiologic Studies Depression Scale (CES-D scale) were administered to every patient as outcome measures.Results: Body composition parameter results showed that sarcopenic patients had statistically lower values as fat mass, lean body mass and skeletal muscle index (p <0.001, p= 0.001, p <0.001, respectively) than those of non-sarcopenic and control group. It was determined that body composition values measured with DEXA, ultrasonographic measures, isokinetic muscle strength assessment, handgrip strength and gait speed had predictive values for sarcopenia. Conclusion: We found that patients with sarcopenic OA were older, weaker, undernourished, and restricted in their level of physical activity in the study in which we identified sarcopenia as approximately 12% in patients with osteoarthritis. Among the methods of determining sarcopenia, ultrasound becomes prominent with its practical, cheap and easily accessible features. We think that our results will increase the awareness of the presence of sarcopenia in OA patients.