Objectives. We investigated the relationship between implementation of workplace smoking cessation support activities and employee smoking cessation. Methods. In 2 cohort studies, participants were 6179 Finnish public-sector employees who self-reported as smokers at baseline in 2004 (study 1) or 2008 (study 2) and responded to follow-up surveys in 2008 (study 1; n = 3298; response rate = 71%) or 2010 (study 2; n = 2881; response rate = 83%). Supervisors’ reports were used to assess workplace smoking cessation support activities. We conducted multilevel logistic regression analyses to examine changes in smoking status. Results. After adjustment for sociodemographic characteristics, number of cigarettes smoked per day, work unit size, shift work, type of job contract, health status, and health behaviors, baseline smokers whose supervisors reported that the employing agency had offered pharmacological treatments or financial incentives were more likely than those in workplaces that did not offer such support to have quit smoking. In general, associations were stronger among moderate or heavy smokers (≥ 10 cigarettes/day) than among light smokers (< 10 cigarettes/day). Conclusions. Cessation activities offered by employers may encourage smokers, particularly moderate or heavy smokers, to quit smoking.