The use of electronic cigarettes (e-cigarettes) is increasing, but their use as a smoking-cessation aid is controversial. The reporting of e-cigarette studies on cessation is variable and inconsistent. To date, only 1 randomized clinical trial has included an arm with other cessation methods (nicotine patches). The cessation rates for available clinical trials are difficult to compare given differing follow-up periods and broad ranges (4% at 12 months with non-nicotine e-cigarettes to 68% at 4 weeks with concomitant nicotine e-cigarettes and other cessation methods). The average combined abstinence rate for included prospective studies was 29.1% (combination of 6-18 months' rates). There are few comparable clinical trials and prospective studies related to e-cigarettes use for smoking cessation, despite an increasing number of citations. Larger randomized clinical trials are essential to determine whether e-cigarettes are effective smoking-cessation devices.