In line with the global trends, electronic cigarettes (e-cigarettes) and heated tobacco products (HTPs) have found their way to the Lebanese market. The present study aims to explore the determinants of e-cigarette and HTP use among young adults in Lebanon. Convenience and snowball sampling were used to recruit participants aged 18–30 residing in Lebanon, who were familiar with e-cigarettes products. Twenty-one consenting participants were interviewed via Zoom and the verbatim transcriptions were analyzed thematically. The outcome expectancy theory was used to categorize the results into determinants and deterrents of use. HTPs were viewed by participants as another mode of smoking. The results showed that most participants perceived e-cigarettes and HTPs to be healthier alternatives to cigarettes/waterpipes and to be used as smoking cessation tools. Both e-cigarettes and HTPs were found to be easily accessible in Lebanon; although, in the recent economic crisis, e-cigarettes have become unaffordable. More research is needed to investigate the motivations and behaviors of e-cigarette and HTP users if effective policies and regulations are to be developed and enforced. Furthermore, greater public health efforts need to be made to increase awareness of the harmful impacts of e-cigarettes and HTPs and to implement evidence-based cessation programs tailored to those modes of smoking.