Glycogen storage disease type I, also known von Gierke’s disease, is a rare, severe autosomal recessive disorder due to a defect in liver, kidney, and intestinal mucosa. The existence of delayed development of the dentition, increased incidence of dental caries, taurodontism, and prolonged bleeding following dental procedures should lead clinicians to consider type I glycogen storage disease. A 10-year-old boy with glycogen storage disease type I whose condition was first diagnosed when he was 4 years of age, was referred to the clinic for multiple caries and evaluation of delayed tooth eruption. On physical examination, the patient was cooperative, with short stature, protuberant abdomen, and growth retardation. Laboratory findings indicated that blood levels of pyruvate, triglycerate, uric acid, and cholesterol were elevated. Intraorally delayed mixed dentition was evident, and approximal caries were found in teeth 55, 54, 52, 51, 61, 62, 65, 74, 84, and 85. The most significant radiographic finding was consistent with taurodontism of the molar teeth. Lateral and posteroanterior cephalometric films showed that dimensions of the craniofacial complex were strongly reduced. Evaluation of the patient’s dental age was approximately 6 years. © 2007 by Quintessence Publishing Co Inc.