Shoulder involvement in RA is underestimated, the incidence of shoulder affection in RA is less than other major joints as hip and knee, but still it represents a significant problem. There is no single clinical, radiologic, or serologic test which enables a diagnosis of RA to be made with certainty. As with other autoimmune rheumatic diseases, the diagnosis depends upon the aggregation of characteristic symptoms, signs, laboratory data, and radiologic findings.Diagnosing RA shoulder requires passing through three important steps :Aٍnalysis of clinical data given by the patient, examination of the patient and investigating the affected shoulder ; confirmation of the diagnosis, synovial biopsy assessment, ssessment of the internal structures of the shoulder joint, staging of the disease.