A survey of infant feeding practices indicated that 40% of the mothers who breast-fed their infants frequently expressed and stored their milk in the home refrigerator/freezer prior to feeding. Effects of different lengths of storage time on the levels of folacin and vitamin C in both term (T) and preterm (PT) human milk were examined. Folacin and vitamin C intakes of most mothers were such that the levels of these vitamins in milk appeared to have reached saturation. Folacin levels in T and PT milk were similar but were lower in both after three months of freezer storage compared to one week of storage. Vitamin C content in PT milk was significantly higher than that in T milk and did not change after three months of freezer storage, whereas the vitamin C level in T milk decreased significantly. After 24 hr refrigeration of T milk, vitamin C content was lower but the folacin level was similar to that observed prior to refrigeration. The findings indicated that T or PT human milk, stored for 3 months in the freezer, would provide the recommended allowance of vitamin C but not of folacin for infants.