To clarify the effect of the clinical dosage of acetazolamide on growth in children with epilepsy or febrile convulsion, the standard scores of height and weight in 17 subjects receiving acetazolamide as an adjunct to unchanged monotherapy of antiepileptic drug were compared longitudinally through four phases: before antiepileptic drug administration, with monotherapy of antiepileptic drug, with acetazolamide in addition to monotherapy, and after acetazolamide discontinuation. The standard scores of both height and weight in the subjects were significantly reduced during the phase of acetazolamide administration. During this period, serum concentrations of potassium and total CO2 decreased while that of chloride increased, suggesting the existence of metabolic acidosis in the subjects. For both height and weight, there was no correlation between the degree of standard score reduction during acetazolamide administration and age at the time of acetazolamide initiation, duration of acetazolamide administration, dosages of acetazolamide, and variety of antiepileptic drugs concomitantly administered with acetazolamide. We speculate that metabolic acidosis induced by acetazolamide suppressed the growth of the subjects and that there were large individual differences in the susceptibility to acetazolamide for growth suppression among patients receiving acetazolamide.