Purpose: This article describes the restorative management of two patients in whom the diagnosis of amelogenesis imperfecta was not made until young adulthood. Materials and Methods: Amelogenesis imperfecta is a variable developmental abnormality of the tooth enamel that affects relatively few persons. Previous case reports have focused largely on the early management of children and young adolescents. However, some patients may not be diagnosed correctly or may not request dental treatment until they are older, as with the two cases presented. In some instances, parents fail to appreciate the importance of early intervention. Results: Both patients required intensive preventive therapy and extensive restorative treatment over several years. The correct sequencing of treatment phases was required to achieve relief of pain and provide satisfactory function and esthetics. Conclusion: The two cases presented illustrate the degree of complexity that extended restorative treatments can involve, especially following severe tooth wear and poor bonding of restorations to the affected enamel. Int J Prosthodont 2003;16:345–349.