Electronic cigarettes (ECIGs) are electronic devices that heat and vaporize a solution that usually contains a mixture of glycerol, propylene glycol, water, flavors and various concen‑ trations of nicotine. ECIGs have 3 key components: A power source, a cartridge containing an atomizer along with a liquid solution and a mouthpiece. The solution (often known as e‑liquid or e‑juice) is heated into an aerosol inhaled by the user. Smoking conventional cigarettes is considered a determinant factor in the development of chronic respiratory diseases, cardiovascular diseases, cancers, and reproductive system dysfunctions. Conventional smoking also causes genome damage and alteration of the transcriptome, due to the amounts of noxious substances emitted during the combustion of these products. Recently, cigarette consumers have begun to use ECIGs as a replacement or substitute practice to help them quit smoking. In addition, an increase in the use of ECIGs and similar devices by young individuals has been reported, which is unsurprising due to the unregulated distribution and sale of these products. The present review article describes and discusses the impact and the noxious effects of substances in ECIGs and other nicotine administration systems on DNA structure, gene expression profile, and epigenetic modification, focusing on the respiratory system and embryonic development.