Hurler syndrome is a rare autosomal recessive disorder of mucopolysaccharide metabolism. It results from a deficiency in lysosomal enzymes responsible for the breakdown of glycosaminoglycans. Affected individuals may show progressive physical and mental deterioration as glycosaminoglycans are deposited in the organs of the body. Bone marrow transplantation (BMT) is effective in improving some of the clinical manifestations of Hurler syndrome. Death is caused by cardiorespiratory failure and usually occurs before the second decade of life. In this case report, the course of dental development was followed over 5 years, from the primary dentition into the permanent dentition, of a child who was successfully treated with a bone marrow transplant in infancy. The timing of bone marrow therapy has significant and variable effect on the stages of tooth development with implications for the long-term maintenance of the dentition.