Background: Brucellosis is a zoonotic disease caused by a Gram negative rod named after Bruce in 1887. It is a zoonosis of worldwide distribution. In Saudi Arabia, the prevalence is high and is attributed to widespread animal husbandry and to the traditional drinking of raw milk. Shoulder brucellosis commonly seen in old population. We have recently treated an old patient diagnosed with brucellosis, who was seen with clinical, radioisotopic, microbiologic, and surgical evidence of shoulder septic arthritis, a rare site of Brucella involvement. Case presentation: A 75 year old male presented with history of fever for the past 10 days with associated right shoulder pain. He was admitted under internal medicine for further investigations for fever of unknown origin. Right shoulder pain was described as generalized dull ache of with gradual onset .Patient Denied any contact with any sheep, animal urine or dairy products, there was no obvious source of ongoing infection and no history of recent trauma. Patient was admitted, orthopedic department was consulted to assess the right shoulder after 24 hour from admission. MRI done which showed joint effusion suggestive of intraarticular collection in support of infective process. Patient was scheduled for Incision and drainage on the same day. Culture was taken intra operative and was sent for microbiology assessment. Wash out was done and a drain was placed and antibiotic started. Infectious disease was then consulted as the patient didn’t improve and they advised to do a full septic screen. Brucella titre was positive for Brucella Melitensis1:80 and Brucella Abortus Agglutinins 1:160. Patient started on doxycycline 100mg PO BID for 12 weeks and streptomycin 1g IM OD for 3 weeks. Two weeks later patient was seen on a follow up appointment at OPD, had no complaints, wound was clean and range of motion of the left shoulder had improved Serial follow up in clinic also showed no recurrent episodes of shoulder pain and there was no active issues and the patient was discharged from the orthopedic service. Conclusion: Musculoskeletal brucellosis is endemic in areas such as Saudi Arabia. Shoulder considered to be a rare site of involvement. Brucellosis should be considered in the line of differential diagnosis, especially in older patients with shoulder arthritis. Early recognition and adequate treatment reduce the suffering of the patients as well as the frequency of relapses.