Resorption of primary teeth is a normal physiologic process, except when it occurs prematurely. Resorption of permanent teeth is considered abnormal, and multiple etiologic factors have been implicated. A significant number of cases are represented by idiopathic resorption. Multiple idiopathic root resorption stands as a separate physiologic entity that has been described as affecting the entire permanent dentition. Multiple idiopathic resorption of primary teeth has not been previously reported. A case is described and a differential diagnosis is provided. The specific radiographic diagnostic criteria for this condition affecting the primary dentition are outlined.