BackgroundTo investigate the association between electronic cigarette (e-cig) use and smoking cessation among smokers who called the Youth Quitline in Hong Kong.MethodsThis longitudinal study collected data on youth smokers' (N=189) use and perception of e-cigs, conventional cigarette smoking behavior, and sociodemographic characteristics at baseline. Self-reported past 7-day point prevalence of abstinence (PPA) was assessed in the 6-month telephone follow-up. Linear and logistic regressions were used to estimate the association of e-cig use with quitting cigarette smoking and other cessation-related outcomes.ResultsE-cig users were younger, more addicted to nicotine, and less ready to quit (all P<0.05) at baseline. The PPA rate was lower in e-cig users (13.4% vs. 20.8%) at follow-up. E-cig use was not associated with PPA at the 6-month follow-up (odds ratio (OR): 0.56, 95% CI: 0.24 to 1.35), but it was nonsignificantly related to more cessation attempts (raw coefficient (b): 1.26, 95% CI: -0.13 to 2.66). Among those who still smoked, e-cig use was nonsignificantly associated with intention to quit smoking (OR: 0.55, 95% CI: 0.15 to 2.05), nicotine dependence (Fagerström score, b: 0.75, 95% CI: -0.39 to 1.90), and perceptions on quitting cigarette smoking.ConclusionE-cig use was not associated with successful smoking cessation among Youth Quitline smokers.