Background: the sternoclavicular (SC) joint is a real diarthrodial joint that can be affected during the route of RA; but, its scientific implications appear to remain under estimated through the rheumatology network. In every day clinical practice, traditional radiography is taken into consideration the usual imaging approach for assessing SC joint involvement; unfortunately, it can constitute a problem inside the diagnostic evaluation because it provides little data regarding gentle tissue involvement. Moreover, it's far much less sensitive than different imaging techniques for assessment of bony abnormalities. Computed tomography (CT) is considered the gold widespread for detection of bone erosions at different joint degrees, inclusive of the SC joint, its major disadvantage is associated with ionizing radiation. The value of magnetic resonance imaging (MRI) is remarkable as it allows identification of bone marrow edema, greater-articular abnormalities, disc and cartilage lesions, and synovial membrane involvement. However, its use is regularly constrained due to its high price. Currently, ultrasound (US) is right extensively common imaging approach in each clinical exercise and in rheumatology studies to visualize joints and tender tissues. To date, there is a regular frame of evidence assisting its validity, reliability, and feasibility inside the evaluation of persistent inflammatory arthritis and its higher sensitivity than scientific exam in the analysis of synovitis, enthesitis, and tenosynovitis in these patients.Aim of the Work: this work aimed to describe the prevalence of sternoclavicular (SC) joint involvement and the relationship between clinical and ultrasound (US) findings in patients with rheumatoid arthritis. Patients and Methods: the ethical approval was obtained from the hospital ethical research committee and each patient participated in this study signed in informed consent. The present study was conducted on a hundred and twenty patients; their age ranged from 20 to 50 years. They were categorized into 2 groups a- 60 patients knowns as RA, b-60 normal control subjects. They were recruited from Physical Medicine, Rheumatology and Rehabilitation Department of Sayed Jalal and Al-Hussein, Al-Azhar University Hospitals, during the period from April 2018 to October 2018.Results: ultrasound revealed a high prevalence of sternoclavicular joint involvement in patients with rheumatoid arthritis than clinical findings. Conclusion: the present study provided US evidence that reveals a higher prevalence of SC joint involvement in patients with RA than in age- and sex-matched healthy controls. US was extra sensitive than medical examination for detecting SC joint involvement in RA. The correlation amongst US synovitis, intraarticular PD and the DAS28 showed that SC joints actively participate within the systemic inflammatory manner of RA. The precise position of US within the assessment of the SC joint in sufferers with RA is but to be mounted firmly in the rheumatologic examination