CPPD deposition disease is a common and potentially severe arthropathy. Hyperparathyroidism, hemochromatosis and hypomagnesaemia can favour chondrocalcinosis and must be looked for in early disease (< or =60 years). Chondrocalcinosis can cause severe attacks of inflammatory arthritis (pseudogout) as well as various forms of chronic arthropathies including pseudo RA, pseudo OA and pseudo neuropathic joint disease. Diagnosis is based on synovial fluid analysis, (positively birefringent CPPD crystals) and X-rays (punctuated and linear radio densities in cartilage). NSAIDs and i.a. or systemic glucocorticoids are the most useful treatments. Colchicine can be effective in recurring pseudogout, and magnesium for attacks' prevention. Methotrexate proved effective in a small uncontrolled series, and can be used when other treatments fail.