Electronic cigarettes (e-cigarettes) reached the market without either extensive preclinical toxicology testing or long-term safety trials that would be required of conventional therapeutics or medical devices. E-cigarettes are considered a tobacco product and as such have no manufacturing quality or safety standards. A growing body of evidence documents severe harms from e-cigarette use, including injuries from product explosions, nicotine poisoning, and severe lung diseases. Commonly used e-cigarette components have significant inhalation toxicity. Emerging evidence from laboratory studies suggests substantial reason for concern for long-term harms, including risk for cardiovascular disease, chronic obstructive lung disease, and cancer. Rather than helping people stop smoking, e-cigarette use is associated with reduced rates of smoking cessation among current smokers and an increased risk of relapse to smoking among former smokers. The World Health Organization advises, “Unlike the tried and tested nicotine and non-nicotine pharmacotherapies that are known to help people quit tobacco use, WHO does not endorse e-cigarettes as cessation aids.” Careful evaluation of all the available research justifies a strong recommendation that healthcare providers should neither prescribe nor recommend e-cigarettes for persons who are tobacco dependent. If a patient is dependent on e-cigarettes, the healthcare provider should provide counseling and treatment (of nicotine dependence) to help the patient to stop their e-cigarette use.