BACKGROUND: Smoking costs at work affect both employers and employees. These costs are a result of a combined loss of productivity, time off work due to illness, smoking breaks and increasing insurance costs. OBJECTIVES: This study aims to evaluate the economical impact of a 12 week smoking cessation program with varenicline from an employer perspective in  a medium size Mexican-Corporate setting. METHODS:  A decision tree was built in order to estimate the two endpoints of the program: resource used in terms of costs and productivity gains in labor hours, in a three year horizon. Smokers enrolling in the program were assumed to be the proportion of people who reported being very much indeed interested on quitting smoking in a 2005 UK survey (27%). A promotional cost of a 12 week combo-pack of varenicline was provided by the manufacturer. A literature review was performed in order to obtain smoking specific data of the country and response rates. Labor costs were retrieved from the Mexican National Institute of Statistics and Geography (INEGI).  A base scenario of a medium sized company  (250 employees) was assumed to show the potential benefits of the program. RESULTS: Assuming a 250 employees company and a shared proportion of 50% of the costs of the program between employees and employers, companies would have to invest US$178 per employee only at the first year, and have potential savings of US$228 for each of them after 3 years. At the same circumstances the net productivity gains per programme participant would be in an amount of 70.8 hours. CONCLUSIONS: This research showed that if mexican employers invest in a smoking cessation program, significant productivity gains and savings could be reached in a 3 year horizon.