Modifications in the preparation of food served in a boarding high school during a 5-week period were successful in decreasing the sodium content of a variety of food products by an average of 51%. Such food was, in general, well accepted. The ratings of specific reduced-sodium food products equaled those of similar products containing "usual" amounts of sodium. Food diaries kept by students gave estimates of total sodium intake comparable with those measured by laboratory analysis of 24-hour food collections. Food diaries collected from an average of 70 volunteers per week indicated that during the reduced-sodium period, the total sodium intake of students, including that from dining hall food, snack food, and food consumed outside the school, decreased from 136 mEq (3 gm sodium, 8 gm salt) to 88 mEq (2 gm sodium, 5 gm salt), a reduction of 35% (p less than .0001). The impact of salt added at the table was very small; the choice and the quantity of foods consumed were the main determinants of sodium intake. The results indicate that foods can be prepared with appreciably less sodium and still be highly acceptable to young people.