Rickets and osteomalacia result from a variety of inherited and acquired conditions, but affected individuals present with striking stereotypical features. In most cases, the bone disease can be cured, or at least improved, with appropriate therapy for the specific metabolic abnormality. In this article, the author provides a discussion of vitamin D metabolism and a detailed description of the clinical presentation, diagnosis, evaluation, and treatment of rickets and osteomalacia. He stresses the importance of orthopedic surgeons' awareness of these metabolic problems so that they may play a more active role in the diagnosis of these disorders and the effective management of the skeletal complications.