Dai H, et al. - Researchers conducted the study for analyzing the prevalence and correlates of self-reported youth observation of e-cigarette use on school grounds. Data from the 2019 National Youth Tobacco Survey (N = 19,018) were analyzed in order to investigate the prevalence and factors associated with youth observation of e-cigarette use in or around the school. Around 63.9% of students (16.8 million) reported noticing youth use of e-cigarettes in or around the school in 2019, with the bathroom or locker room as the most popular place (33.2%). Among never tobacco users ( n = 11,518), observation of vaping in schools was related to higher odds of being susceptible to smoking cigarettes and using e-cigarettes, particularly among middle-school students. On school grounds, e-cigarette use is common, and youth observation of vaping in schools may increase the likelihood of tobacco use being initiated in the future. School vaping policy and education programs are required to curb the use of young e-cigarettes.