Background and aims Evidence on the effectiveness of electronic cigarettes (ECs) to facilitate abstinence from smoking is limited. The current study aimed to estimate the relative effectiveness of ECs and smoking cessation medication compared with using no help, accounting for frequency of use of ECs. Design Four consecutive wave‐to‐wave transitions (waves 1–2, 2–3, 3–4 or 4–5) of a longitudinal online survey collected between 2012 and 2017 were analysed. Time between waves ranged between 12 and 17 months. Cigarette smokers at the baseline wave who attempted to quit smoking between waves were included. Setting United Kingdom Participants A total of 1155 respondents (aged 18–81, 56.1% male, 64.6% in social grade C2DE, 93.8% white) provided 1580 pairs of observations for the primary analysis. Measurements Primary outcome: abstinence from smoking for at least 1 month at follow‐up; secondary outcome: at least 1 month's abstinence from smoking between baseline and follow‐up. The main predictor was stop smoking aid used (No help, nicotine replacement therapy only, smoking cessation medication only, disposable/cartridge EC, refill/modular EC, combination), adjusted for demographics. Findings Primary Compared with using no help, the odds of abstinence were increased by daily use of disposable/cartridge ECs (OR = 3.31 (1.32, 8.26), P = .010) and daily use of refill/modular ECs (OR = 5.47 (2.70, 11.11), P < .001). Odds were reduced by non‐daily use of disposable/cartridge ECs (OR = 0.23 (0.08–0.63), P = .005), and by use of disposable/cartridge ECs to quit and no longer using at follow‐up (OR = 0.10 (0.16–0.62), P < .013). Secondary Results were similar to the primary outcome; however, odds of abstinence were also increased by use of smoking cessation medication (OR = 4.15 (1.79, 9.62), P = .001). Conclusions When used daily, electronic cigarettes appear to facilitate abstinence from smoking when compared with using no help.