Riboflavin status of 17 insulin-dependent diabetic mellitus(IDDM) patients in growing period was evaluated as a function of energy intake and expenditure, biochemical nutritional status and diabetic control indicators. Compared with recommended dietary allowances for Koreans(RDA, 1989), only 35.3% of subjects was at good levels of all nutrients intakes and 52.9% of subjects was below normal level of height and weight. Nutrients consumed below RDA levels were energy(=88.5% of subjects), niacin(64.7%), iron(52.9%) and protein(23.5%) respectively. The riboflavin status was within normal range by urinary riboflavin excretion but 17.6% of subjects was evaluated as showed riboflavin deficiency by erythrocyte glutathione reductase activity coefficient(EGRAC). Correlation between riboflavin intake, urinary riboflavin excretion, EGRA level and diabetic duration were not statistically significant. Correlation analyses indicated that EGRA level was inversely correlated with thiamin, niacin and cabohydrate intake. No significant correlations were found between the EGRA and glycosylated hemoglobin A1(HbA1) (r=-0.464, p=0.129). From this study, it is suggested that IDDM subjects need to maintain balanced diet containing nutrients above RDA for individual activity during growing period. It needs more study whether the current recommended riboflavin allowance is adequate for diabetic patients.