A healthy 37-year-old man presented with complaints of swelling and pain involving the left sternoclavicular joint region of three weeks  duration in September 2017. There was no history of fever, loss of appetite or loss of weight. He was treated with antibiotics for one week by his family doctor. The patient had no history of drug abuse or high-risk behavior. He has primary infertility for which he was investigated and received hormonal therapy. There was no family history of tuberculosis. On general physical examination, his vital signs were normal. Body mass index was 34 kg/m2. No cervical or axillary lymphadenopathy. There was a swelling measuring 4x4 cm over the left sternoclavicular joint region. The skin over the swelling was stretched and erythematous (Figure 1). It was non-tender and soft inconsistency. Movements of the left shoulder joint were normal. The chest was clear; heart sounds were normal. Abdominal examination was normal. Full blood count revealed haemoglobin of 11.8 g/dl, white cell count of 6.8x103 mul, neutrophil 57.7%, lymphocytes 33.4%, eosinophil 2.6%, monocyte 5.7%, basophil 0.6%. The erythrocyte sedimentation rate (ESR) was elevated to 70 mm/hour, and the test for C-reactive protein (CRP) was positive (thirty milligrams per liter). A serological test done for HIV was negative. A tuberculin skin test was also negative. Ziehl Neelson stain was negative. Chest radiograph revealed normal lung fields with suspicious of the irregularity of right sternoclavicular joint. A computerized tomographic scan showed extensive destruction involving cortices of clavicular as well as the sternal end of the joint with loculated collection in the subcutaneous tissue at the left side of lower neck extending into the left sternoclavicular and first sternochondral joint with the impression of septic arthritis in these two joints (Figure 2). Ceftriaxone one gram intravenously was commenced. An open biopsy was performed. Frank yellow creamy pus found in the subcutaneous communicating with the joint. Culture of pus identified as Mycobacterium tuberculosis. Biopsy of the abscess wall showed multiple granulomatous lesion with large caseous necrosis (Figure 3, Figure 4). A diagnosis of tuberculous arthritis was made, based on the presence of granulomatous lesion and mycobacteria in the histological material. A hospital stay of the patient was 10 days. lsoniazid (300 mg per day), rifampin (600 mg per day), ethambutol (1600 mg per day), pyrazinamide (2000 mg per day), pyridoxine (20 mg per day) were administered for two months and then isoniazid (300 mg per day), rifampin (600 mg per day) and pyridoxine (20 mg per day) were continued for seven months. At a follow-up examination ten months after treatment, the patient recovered well and there was no evidence of recurrence of the infection clinically and by laboratory investigations, but he did show mild pain due to osteoarthritis of the sternoclavicular joint.