Evidence- and consensus-based guidelines for the diagnosis and treatment of reading and/or spelling disorders in children and adolescents are now available for the first time. Reading and spelling abilities should be systematically and comprehensively reinforced, and potential comorbid disorders should be sought and treated appropriately. The efficacy of many treatments now in use has not been documented; if they are to be used in the future, they must be tested in randomized, controlled trials. For adult sufferers, adequate diagnostic instruments and therapeutic methods are not yet available.