A 14-year-old girl with juvenile idiopathic arthritis (JIA) was admitted for joint aspiration and intra-articular injection of steroids under general anaesthetic. A small amount of fluid was aspirated from a knee containing a large effusion using a 21-gauge needle, but nothing further could be obtained despite repositioning the needle and placing pressure on the joint externally. A 14-gauge needle was then inserted and 100 mL of fluid containing particulate matter consistent in appearance with rice bodies was extracted (see picture). Rice bodies were originally described in association with tuberculous arthritis. They were called rice bodies because of their macroscopic similarity to grains of polished white rice. They are now most commonly associated with rheumatoid arthritis but are also seen in other inflammatory arthritides including JIA. Rice bodies are a non-specific response to synovial inflammation. They are thought to arise as a result of synovial proliferation and degeneration, or as the product of synovial microinfarction with affected fragments falling into the joint space and being covered by fibrin layers. They consist of a heterogeneous group of particles that may contain collagen, fibrinogen, fibrin, fibronectin, mononuclear cells and blood cells. A clear relationship between the presence of rice bodies and the severity of arthritis has not been demonstrated. For the knee, particularly, if there is a significant effusion present but difficulty in joint aspiration using a standard 19 or 21 gauge needle, rice bodies may be the cause and the use of a larger gauge needle may result in their successful removal.