We report on the development of the Hospitality Scale, which measures two aspects of adolescents' perception of social capital in school-the extent to which they perceive that they have social capital and the extent to which they provide social capital to others. The scale was developed in reference to the literature exploring adolescent social isolation and social tolerance, as well as constructs developed in research on adults, especially related to psychological sense of community and collective efficacy. We examine the reliability of the scale and the association between scale scores and behavioral factors that may reflect social isolation.