Musculoskeletal involvement is common in patients with systemic lupus erythematosus (SLE). The inflammatory process in SLE is traditionally considered to be localized at synovial tissue areas while enthesis is not included among the possible disease targets. Entheses included in the MASEI Madrid ultrasonographic enthesitis index were scanned in a case control study of 50 SLE patients and 30 healthy controls in an MSUS study aimed at assessing enthesitis in patients with systemic lupus and arthritis .Clinical enthesitis was found in 97 of 100 knees (97%) of patients affecting mainly patellar tendon more than quadriceps . Ultrasound (US) examination revealed the presence of one or more abnormalities (entheseal thickening, enthesophytes, erosions, bursitis) with 58 finding in asymptomatic right and left knees but 103 finding on symptomatic knees in the form of pain and swelling and limitation in the range of movement . MSUS is a sensitive tool for the detection of enthesitis in SLE patients. enthesitis, both clinical and ultrasound-proven, is common in SLE patients.