Idiopathic infantile arterial calcification (IIAC) is a rare hereditary, fatal disease. Death occurs usually within the first 28 months of life. IIAC is characterized by calcifications along the internal elastic membrane and proliferation of the intimal layer of muscular arteries. Specific therapy consists of administration of diphosphonates, but its effectiveness has been a matter of controversy. We report a case treated with diphosphonates which has had an unusual outcome.