We describe the clinical characteristics of 5 Taiwanese children with glutaric aciduria type I treated in a single medical center. Macrocephaly was present in 5 of these patients, psychomotor retardation in 4, and neurological regression in 2. Diagnosis was made prenatally in 1 patient due to an affected sibling. Low lysine/tryptophan formula, carnitine, and vitamin B2 were given to all patients. All patients disliked and could not adhere to the special formula and medications. Four older patients had neurological deficits prior to the start of the regimen. Among them, 1 died of sepsis and malnutrition. Only the prenatally diagnosed child did well at age 22 months. Mutational analysis, performed by polymerase chain reaction and sequencing, revealed an IVS10-2A>C defect in all 5 patients, and 2 siblings were homozygous. In addition, 2 novel mutations were detected. We conclude that GA I might not be as rare in Taiwan as previously thought. IVS10-2A>C is a common mutation in the Taiwanese population, whose genotypes are quite different from those of Caucasians.