The effect of 4, 8, and 12 months' storage at 50°, 65°, and 80°F. on the ascorbic acid, carotene, niacin, riboflavin, and thiamine content of seventeen lots of canned fruits and fruit juices has been studied. Comparisons were also made as to the effect of a year's storage, in nine warehouses located in cities throughout the United States, on the ascorbic acid and thiamine content of tomatoes and orange juice. The canned foods, held under constant temperature conditions, at 50°F. showed no significant losses in ascorbic acid, thiamine, or carotene.Tomatoes showed a significant loss in niacin after 8 months of storage regardless of the temperature employed. In general,A NUMBER of studies on the nutritive value of canned fruits and vegetables have been reported in the last few years. The results point out that canned foods are important sources of the essential food nutrients. Since, however, the unstable character of several of the vitamins suggests the possibility of appreciable losses during storage, definite information is needed as to the effect of time and temperature on these nutrients. A few studies of limited scope on,the effect of such variables in storage conditions on vitamin retention in commercially canned foods have been published. These data show that both time and temperature affect the retention of ascorbic acid (7, 15, 22, 28) and that temperature has a limited effect on carotene retention but a marked effect on thiamine (7).To widen the scope of information on this subject a more extensive investigation was planned of the effect of time and temperature of storage on the retention of ascorbic acid, carotene, niacin, riboflavin, and thiamine in commercially canned fruit and