1. A case of vertebra plana (Calvé) is described and serial radiographs throughout the course of the disease are presented. 2. The initial radiographs showed a vertebra of normal depth which collapsed to a thin disc in fifteen days. Since the symptoms had begun twelve days before the first examination the total time taken to reach this stage was twenty-seven days. 3. The literature has been reviewed for evidence of the underlying pathology of vertebra plana. In the case described biopsy of the affected vertebral body was not carried out, and thus the nature of the underlying change could not be determined.