Objective This review summarises the impact of mass media campaigns on promoting quitting among adult smokers overall and for subgroups; the influence of campaign intensity and different channels; the effects of different message types. Methods The present work updates two reviews published in 2008 by searching databases using a standard search string. Articles in languages other than English were excluded, as well as letters and editorials. Screening of abstracts yielded 194 potentially relevant articles. Abstracts were evaluated by 2 authors, excluding articles that focused on populations other than adults and according to other specified criteria, resulting in 26 studies reported in 29 articles. Studies were categorised as (a) population-based studies of campaign effects and (b) studies comparing message types, using either population-based or forced exposure methods. Findings of subgroup differences for each study were noted, as well as study strengths and limitations. Results Overall, the studies have strengthened the evidence that mass media campaigns conducted in the context of comprehensive tobacco control programmes can promote quitting and reduce adult smoking prevalence, but that campaign reach, intensity, duration and message type may influence success. Achievement of sufficient population exposure is vital, especially for lower socioeconomic status smokers, with television remaining the primary channel to effectively reach and influence adult smokers. Studies comparing different message types found negative health effects messages most effective at generating increased knowledge, beliefs, positive perceived effectiveness ratings, or quitting behaviour, while there was more mixed evidence for other message types. A few studies further suggest that negative health effects messages may also contribute to reductions in socioeconomic disparities in smoking. Conclusions Mass media campaigns to promote quitting are important investments as part of comprehensive tobacco control programmes to educate about the harms of smoking, set the agenda for discussion, change smoking attitudes and beliefs, increase quitting intentions and quit attempts, and reduce adult smoking prevalence. Jurisdictions should aim for high reach and consistent exposure over time with preference towards negative health effects messages.