Internet is important resource of health-related information and health services. Factors associated with higher level of online health (eHealth) literacy among adolescence have been understudied. The aim of this study was to assess psychometric properties of the eHealth Literacy Scale (eHEALS) in Serbian language and to evaluate eHealth literacy among adolescents in Serbia. The study was carried out in four high schools in Belgrade, Serbia in the period December 2016 to January 2017. A total of 702 students comprised the study sample. The eHEALS was translated according to internationally accepted methodology and its psychometric properties were analyzed. The Cronbach’s alpha coefficient for the entire eHEALS was 0.849. On exploratory factor analysis we obtained two-factorial structure. Our adolescents reported low confidence in knowing what health resources are available online. High confidence was observed for knowing how to use and how to find health information online. There was no difference in eHEALS score between genders or between school years. After adjustment for gender, type of school program, parental marital status, fathers’ education level and household income, being female was associated with higher eHealth literacy (B = 1.12, 95% confidence interval 0.07–2.18; p = 0.036). Serbian version of the eHEALS is a valid instrument in assessment of online health literacy and can be further used in evaluation of eHealth literacy in other population groups in Serbian language. It is advised that some classes in school are dedicated to appraisal and use of online health websites. This could be achieved through peer-education.