Data from the Third National Health and Nutrition Examination Survey (NHANES-III), conducted in 1988-94, were used to compare the nutrition and health characteristics of participants and nonparticipants in the Food Stamp Program (FSP). FSP participants were compared with two groups of nonparticipants-those who were income-eligible for the FSP (income at or below 130 percent of poverty) and those with higher incomes (income above 130 percent of poverty). This research was designed to establish a baseline from which to monitor the nutritional and health characteristics of FSP participants and nonparticipants over time.