RESUMEN
Ostheoarticular tuberculosis is a chronic disease that destroys bones and joints. A woman presented to Imam Hossein hospital because of pain, joint swelling and limitation of joint motion in her right knee. Her chief complaints were pain, swelling and limitation of right knee motion from 2 week ago. There was a large mass around the knee with spontaneously drainage after one week of swelling. At admission, she had mild fever, swelling in the posterior of right knee joint, tenderness and limitation of join motion. ESR was reported 55 mm/ 1 hour. Imaging showed narrowing of the joint cleft. Acid-fast staining organism of joint fluid was positive. After confirming tuberculosis of knee joint, standard anti-tuberculosis regimen was started. After two months of treatment, symptoms and signs were improved