Background: Previous research has shown that youth who are homeless engage in high-risk behaviors. However, there has been little information published on nutritional and physical activity behaviors in this population, and studies comparing homeless youth in school with their non-homeless peers are scarce. This study compares weight-related risk behaviors of public high school students in Massachusetts based on homeless status. Methods: We obtained data from 3264 9th through 12th grade students who participated in the 2005 Massachusetts Youth Risk Behavior Survey. Multivariable logistic regression, controlling for gender, grade, race/ethnicity, and sexual orientation, was performed to assess the relationship between homeless status as defined by the McKinney-Vento Homeless Assistance Act and weight-related indicators. Analyses were weighted and adjusted for the multistage complex sampling design. Results: Of this sample, 4.2% reported being homeless (n = 152). Higher prevalence of homelessness was found among males, racial/ethnic minorities, sexual minorities, and students who were not in a traditional grade level. The distribution of body mass index was similar among students who were homeless and non-homeless (underweight 4.0 and 3.0%, and overweight 27.1 and 27.1%, respectively). Homeless students were more likely than non-homeless students to report disordered weight-control behaviors including fasting (aOR 2.5, 95% CI 1.4-4.5) and diet pill use (aOR 3.3, 95% CI 1.6-6.9). Conclusions: More than 4% of public high school students in Massachusetts meet the federal definition of homelessness. These students are at high risk for disordered weight-control behaviors. Policy decisions at the school, state, and federal levels should make a concerted effort to target these students with social services and nutritional interventions. (Contains 3 tables.)