A new case of association between Bartter's syndrome and chondrocalcinosis is reported. The patient was shown to have marked hypomagnesemia. Indomethacin and magnesium therapy was started and resulted in increased magnesemia, even if it did not reach normal levels. There was complete remission of articular symptoms and no progression on the radiological picture after 2 years of continuous magnesium and indomethacin therapy. The 7 available family members were studied to assess the possible presence of a familial form of chondrocalcinosis and/or hypomagnesemia. The literature is reviewed and reports of previously described associations between Bartter's syndrome and chondrocalcinosis are summarized. The possible role of hypomagnesemia in predisposing to deposition of calcium pyrophosphate dihydrate crystal in cartilagine is also discussed.