Abstract Background: Musculoskeletal (MS) ultrasonography (US) plays an important role in detection of subclinical abnormalities in rheumatoid shoulder, which allows early treatment. MS US is a useful tool in the evaluation of inflammatory RA arthritis being more sensitive than clinical examination. It is a useful tool in detection of disease progression and follow up post treatment. Dynamic sonography allows accurate evaluation of multiple musculoskeletal disorders that are best or only shown during movements. Aim of Study: To assess the diagnostic value of shoulder US in the evaluation of rheumatoid arthritis with shoulder pain as a disease activity parameter providing a semi-quantitative scoring system for synovitis and sub acromial impingement being frequently involved to monitor treatment response in correlation with other clinical and laboratory parameters. Patients and Methods: This study included 51 unilateral shoulder joints in 51 patients (34 females and 17 males) with mean age of 39.8 years. All patients were RA diagnosed. Musculoskeletal ultrasound were performed for all patients with static (including gray scale and power Doppler modes) and dynamic manners for semi-quantitative scoring system of synovitis, erosions and sub acromial impingement. Follow-up US were repeated after 3 to 6 months of treatment. Results: 47(92.2%) RA patients studied had synovial thickening and synovitis on B-mode and PD with variable semi-quantitative scoring grades of severity. 26 patients showed improvement on PD after treatment by recording better scoring compared to their baseline before treatment. Pre-treatment dynamic ultrasonography found that most impingement cases (45.1%) were classified as grade 2and 13 patients of them improved after physiotherapy treatment. In our study 41 (80.4%) of the patients received corticosteroids; 12 patients had progressive disease status with subsequent treatment complications. Conclusion: US is an informative tool in assessment of shoulder pain in RA patients whether static or dynamic US that provides a semi-quantitative scoring system for synovitis and erosions as well as dynamic US scoring system in sub-acromial impingement cases. This scoring system is effective in the evaluation ofdisease progression and treatment response parallel to other clinical and laboratory parameters. US is a specific imaging tool, but with poor sensitivity in supraspinatus pathologies compared to MRI.