The Interpersonal Support Evaluation List-12 (ISEL-12; Cohen, Mermelstein, Kamarck, & Hoberman, 1985) is broadly employed as a short-form measure of the traditional ISEL, which measures functional (i.e., perceived) social support. The ISEL-12 can be scored by summing the items to create an overall social support score; three subscale scores representing appraisal, belonging, and tangible social support have also been proposed. Despite extensive use, studies of the psychometric properties of ISEL-12 scores have been limited, particularly among Hispanics/Latinos, the largest and fastest growing ethnic group in the United States. The current study investigated the reliability and structural and convergent validity of ISEL-12 scores using data from 5,313 Hispanics/Latinos who participated in the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study. Participants completed measures in English or Spanish and identified their ancestry as Dominican, Central American, Cuban, Mexican, Puerto Rican, or South American. Cronbach's alphas suggested adequate internal consistency for the total score for all languages and ancestry groups; coefficients for the subscale scores were not acceptable. Confirmatory factor analyses revealed that the one-factor and three-factor models fit the data equally well. Results from multigroup confirmatory factor analyses supported a similar one-factor structure with equivalent response patterns and variances between language groups and ancestry groups. Convergent validity analyses suggested that the total social support score related to scores of social network integration, life engagement, perceived stress, and negative affect (depression, anxiety) in the expected directions.