The chapter initiates with a short introduction to electronic cigarettes (e-cigs) with their developmental history being outlined. The reported harmful and potentially harmful chemical constituents associated with vaping are briefly introduced. Next, recently reported chromatographic and spectroscopic approaches for the detection and quantitation of chemical entities in e-cigs and their resulting aerosols are discussed. The applicability of direct analysis in real-time mass spectrometry without the need for chromatographic separation was highlighted. The findings of these studies on the basis of identification and/or quantitation of chemical entities and their concentrations in e-liquids and aerosols are summarized. The chapter concludes by providing insights into the importance of applying analytical approaches for a more comprehensive surveillance monitoring of e-cigs to deduce their potential toxicity or carcinogenicity, which could present potential health risks for users.