This report describes the symptoms, clinical course and radiological features in three cases of idiopathic carpotarsal osteolysis. Before signs of extensive osteolysis were noted, one of our patients showed flattening, loss of harmonious curvature and minimal osteoporosis of carpal and tarsal bones, all early radiological signs which have not been described previously. We discuss the findings, classification and our ideas as to the cause of the disorder.