At the end of this session interested smokers could leave their contact information. This informative session was about the ACt but it was also mentioned that some scientific measurements would take place. Smokers were first informed by their Human Resource department about an informative session preceding the actual ACt that was going to take place. Smokers could follow the training for free. Participants in the experimental group were recruited between January 2011 and May 2012 through companies that decided to purchase the ACt for their smoking employees. The company “Bewegen Werkt” markets the ACt in companies. This is what the present study is about: A quasi-experiment in which smoking employees in companies are exposed to the ACt, while their abstinence rate assessed after 13 months is compared to that of baseline-matched smokers recruited from the general population. Thus, in this case the treatment package is “ACt in companies”. When the control group is recruited from the general population, the design will show whether it is fruitful to expose smokers “in companies to the ACt”. When the control group is recruited from other companies, the design will show whether it is fruitful to expose smokers in companies “to the ACt”. In the present study of ACt in companies, an independent control group might be recruited from other (similar) companies but also from the general population. The composition of the control group further determines the exact research question the quasi-experiment will address. Therefore, in the present study, the most important demographic variables (e.g., age, gender), smoking behavior related variables (e.g., FTND), and psychological variables (motivation to quit, self-efficacy) were assessed at pretest to test and shape the similarity. Therefore, the quality of such a quasi-experimental design primarily depends on the baseline similarity on relevant variables of the participants in the ACt group and those in the control group. In a quasi-experiment the practice of the ACt is monitored and the changes are compared to the changes in an independently recruited cohort of smokers, implying that no randomization took place. Therefore, we tested the ACt in companies in a quasi-experiment. For example, once companies are interested in the ACt, they want to be certain that they can offer the ACt to their smokers, and they find it less desirable to let their smokers be randomized or to be randomized as a (department of) a company to the ACt condition or a control condition. This implies that the test of effectiveness must be conducted within the setting of the companies, taking into account the demands and desires of companies that join the study. In the present study we aimed to assess whether providing the ACt to smokers in companies is effective in stimulating abstinence from smoking. For example, recruited smokers might be randomly assigned to an ACt condition or to a no-intervention control condition. The best scientific design to test whether the ACt method incorporates effective ingredients is the RCT. Thus, although the ACt seems widely used, very limited evidence is available with regard to its effectiveness. Two other studies in AC smoking cessation clinics reported percentages abstinence up to 26%. One study reported that of 357 smokers exposed to the ACt in a company, at least 40% reported point-prevalence abstinence after 12 months, while in the cohort study (N = 510) 51% of the smokers reported abstinence about 3 three years after the ACt. Only percentages of abstinence from cohorts of smokers who followed the training are published. However, few data are available on the effectiveness of the training. There are stop smoking seminars in more than 150 cities in over 45 countries worldwide” In the Netherlands, the licensee holder of the ACt primarily provides the training through companies, exposing about 1,500 smokers to it each year. The Allen Carr website states they have: “… sold over 10 million stop smoking books in 57 countries in more than 38 languages Every year Allen Carr’s Easyway To Stop Smoking Clinics and online quit smoking programmes cure over 50,000 smokers. The method also has been published widely in book form. Allen Carr’s “Easyway to Stop Smoking training” (ACt) is an one-session smoking cessation group training that is provided by licensed organizations that have the permission to use the Allen Carr method.