The global food crisis has led to increased interest in food insecurity and its causes and consequences. Much of the focus however has been on mothers and young children, with little attention paid to the possible impacts on the large population of youth in developing countries. The objectives of this paper are to (1) draw attention to the food insecurity experience of a forgotten population, youth; (2) test whether the prevalence of food insecurity among Ethiopian adolescents is increasing with the rising cost of foods; and (3) to identify some individual, household, temporal, and spatial predictors of vulnerability. Data are drawn from a baseline survey in 2006 and a follow-up survey round conducted in 2007 of an ongoing population-based longitudinal study of approximately 2,100 youth living in southwestern Ethiopia. Results show high levels of food insecurity among youth, a marked increase in the experience of food insecurity among youth, and a bias in vulnerability toward youth in the poorest households and in rural households. During the intersurvey period boys were also more likely than girls to become food insecure. This latter finding effectively eliminates the gender bias in food insecurity observed in the baseline survey. Youth who became food insecure between survey rounds were also more likely to report worse health in 2007 than in 2006. Collectively our results suggest that youth are not being adequately buffered from food insecurity, and that generalizations about the current food crisis may be too broad and, thus, misrepresent vulnerable groups. Future research should focus on how to best protect vulnerable youth from the experience of food insecurity and its consequences.