Dentinogenesis imperfecta (Hereditary Opalescent Dentin) is a genetic disorder of tooth development. Teeth are discolored (most often a blue-gray or yellow-brown color) and translucent. Teeth are weaker than normal, making them prone to rapid wear, breakage, and loss. In cases where clinical crown structure is severely attrited in dentinogenesis imperfecta, surgical crown lengthening is required prior to prosthetic rehabilitation. Crown lengthening procedures provide adequate tooth structure necessary for retention form, ferrule effect during tooth preparation and impression procedures. It is important to maintain biological width during crown lengthening. This case report present the management of worn out maxillary and mandibular anterior teeth of a 17 year old boy by crown lengthening procedure who was diagnosed with dentinogenesis imperfecta. Keywords: dentinogenesis imperfecta, crown lengthening, prosthetic rehabilitation, biologic width, attrition, ferrule effect