Electronic nicotine delivery systems (ENDS) have become the most popular tobacco products among young people, yet ENDS marketing remains unregulated, and its effects on ENDS use behavior across age groups is poorly understood. In this study, using a longitudinal design, we examined how recall of ENDS marketing through 5 different channels predicted subsequent ENDS initiation up to 2.5 years later among youth (ages 12-17 years) and young adults (ages 18-29 years).Data were drawn from 2 large cohort studies in Texas. The analysis included school-going youth ( = 2288) and college-going young adults ( = 2423) who reported never having used ENDS at baseline in 2014. Logistic regression was used to assess the influence of recalled ENDS marketing exposure via television (TV), radio or Internet radio, billboards, retail stores, and the Internet on subsequent ENDS initiation, with adjustment for these channels, baseline sociodemographics, other past-30-day tobacco use, sensation seeking, and peer ENDS use.Recall of retail store-based ENDS marketing at baseline was associated with significantly higher odds of subsequent ENDS initiation among youth (adjusted odds ratio [aOR] = 1.99; 95% confidence interval [CI]: 1.25-3.17) and young adults (aOR = 1.30; 95% CI: 1.05-1.61) up to 2.5 years later. Young adult initiation was also associated with recalled ENDS marketing on TV at baseline (aOR = 1.29; 95% CI: 1.03-1.63).Marketing of ENDS at retail stores predicts youth and young adult ENDS initiation, and marketing on TV predicts young adult initiation. Future research and regulation should be used to address the most influential marketing channels.