Nutrition knowledge tests were administered to 1,193 teen-agers in Oregon prior to units on nutrition in health and home economics classes. Mean scores on the test were low, 39.4 +/- 11.6% correct. Teen-agers generally knew the Four Food Groups, appropriate snacks, a single "best" source of nutrients and the basics of weight control. They overestimated the importance and necessary amounts of dietary protein and vitamin C. Most of these teen-agers did not know food sources of nutrients other than the commonly known "best" source. They also had difficulty selecting a nutritious meal unless the meal followed traditional patterns. The nutrition units taught to these teen-agers generally included the Four Food Groups, the relationship of diet to health and food sources of various nutrients. Less than one-third of the units had major emphasis on nutritional needs during pregnancy, nutrition and athletics, retention of nutrients in food preparation or food fads and myths.