BackgroundAdolescents are substantial users of short message service (SMS) and social media. The public health community now has more opportunities to reach this population with positive youth development and health messages through these media. Latinos are a growing and youthful population with significant health risks and needs. This population may benefit from SMS and social media health interventions.ObjectiveTo examine (1) SMS and social media utilization and behavior among Latino youth, and (2) how SMS and social media can be effectively used as a component of public health interventions focused on decreasing sexual risk taking among Latino youth.MethodsA mixed-methods approach, using both quantitative survey data and qualitative interview data, was used to provide a robust understanding of SMS and social media use and behavior for public health interventions. We recruited 428 ninth and tenth grade, self-identifying Latino adolescents to participate in a quantitative survey. Additionally, we conducted five key informant interviews with staff and 15 youth.ResultsWe found that 90.8% (355/391) of respondents had access to a mobile phone either through having their own or through borrowing or sharing one. Of those who had access to a mobile phone, 94.1% (334/355) used SMS, with 41.1% (113/275) sending and receiving more than 100 text messages per day. Of 395 respondents, 384 (97.2%) had at least one social media account, and the mean number of accounts was 3.0 (range 0–8). A total of 75.8% (291/384) of adolescents logged in to their account daily. Of those with a social media account, 89.1% (342/384) had a Facebook account. Youth who took the survey in English were significantly more likely than those who took it in Spanish to have access to a mobile phone (χ2 1 = 5.3; 93.3% vs 86.3%; P = .02); to be high-volume texters (χ2 2 = 16.8; 49.4% vs 25.3%; P < .001); to use the Internet daily (χ2 1 = 5.0; 76.6% vs 66.0%; P = .03); to have a Facebook account (χ2 1 = 9.9; 90.9% vs 79.7%; P = .002); and to have a greater mean number of social media accounts (t 387 = 7.9; 3.41 vs 2.07; P < .001).ConclusionsSMS and social media are pervasive among Latino youth. Program staff and youth perceive these as credible and essential methods of communication in the context of public health programs. Public health interventions must continue to innovate and maximize new ways to reach young people to reinforce public health messages and education.