Electronic cigarette use in adolescence is associated with later cannabis use

•E-cigarette use by age 14 nearly tripled the odds of cannabis initiation by age 17.•E-cigarette use by age 14 more than doubled the odds of age 17 frequent cannabis use.•3 out of 4 e-cigarette and tobacco users by age 14 predicted to initiate cannabis.•Probability of cannabis initiation similar among e-cigarette and tobacco users.