Abstract Objective To summarize findings from qualitative studies on factors associated with smoking cessation among adolescents and young adults. Data sources We searched Pubmed, Psychinfo, CINAHL, Embase, Web of Science, and SCOPUS databases, as well as reference lists, for peer-reviewed articles published in English or French between January 1, 2000, and November 18, 2020. We used keywords such as adolescents, determinants, cessation, smoking, and qualitative methods. Study selection Of 1724 records identified, we included 39 articles that used qualitative or mixed methods, targeted adolescents and young adults aged 10–24, and aimed to identify factors associated with smoking cessation or smoking reduction. Data extraction Two authors independently extracted the data using a standardized form. We assessed study quality using the National Institute for Health and Care Excellence checklist for qualitative studies. Data synthesis We used an aggregative meta-synthesis approach and identified 39 conceptually distinct factors associated with smoking cessation. We grouped them into two categories: (1) environmental factors [tobacco control policies, pro-smoking norms, smoking cessation services and interventions, influence of friends and family], and (2) individual attributes (psychological characteristics, attitudes, pre-quitting smoking behavior, nicotine dependence symptoms, and other substances use). We developed a synthetic framework that captured the factors identified, the links that connect them, and their associations with smoking cessation. Conclusions This qualitative synthesis offers new insights on factors related to smoking cessation services, interventions, and attitudes about cessation (embarrassment when using cessation services) not reported in quantitative reviews, supplementing limited evidence for developing cessation programs for young persons who smoke. Implications Using an aggregative meta-synthesis approach, this study identified 39 conceptually distinct factors grouped into two categories: Environmental factors and individual attributes. These findings highlight the importance of considering both environmental and individual factors when developing smoking cessation programs for young persons who smoke. The study also sheds light on self-conscious emotions towards cessation, such as embarrassment when using cessation services, which are often overlooked in quantitative reviews. Overall, this study has important implications for developing effective smoking cessation interventions and policies that address the complex factors influencing smoking behavior among young persons.