Purpose
Adverse health effects of smoking could be made worse by worker's tobacco use, and combining tobacco use with occupational hazards could enhance the likelihood of occupational disease and injury. This study was aimed to develop a workplace smoking cessation program based on self-determination theory (SDT) and then to examine the effectiveness of the program.

Methods
A quasi-experimental design with nonequivalent control group pretest–posttest design was used. An intervention group (n = 30) received a smoking cessation program using individual counseling and tailored text messaging based on SDT during 12 weeks. Participants in the control group (n = 30) received a smoking cessation leaflet and telephonic follow-up for 3 times.

Results
At 6 and 12 weeks, there were significant differences between the two groups on autonomous regulation, perceived competence, nicotine dependence, tobacco abstinence rate, and exhaled carbon monoxide concentration. At 12 weeks, the abstinence rate in the intervention group was 96.7%, whereas that in the control group was 12.9%.

Conclusion
SDT-based workplace smoking cessation program using individual counseling and tailored text messaging is effective in encouraging autonomous regulation and competence for workers.