Background: Smoking is correlated with coronary heart disease, and further, is one of the risk factors. As smoking is a common addictive behavior in human society, understanding the factors behind the process of smoking cessation will aid current smokers in quitting. Purpose: The study aimed to investigate the influences that motivated inpatients with coronary heart disease to quit smoking. Methods: In this cross-sectional study, inpatients with coronary heart disease were surveyed in a northern Taiwanese hospital. The 122 participants of the study were above 20 years of age (inclusive) and had a history of smoking. The information was gathered with a self-reporting questionnaire. Results: The subjects of the study were mostly aged between 46-65, had been smoking for 21-30 years, smoked 11-20 cigarettes a day, and had an intermediate level of nicotine addiction. The behavior of smoking cessation among the subjects was no significant difference with demographic variables, smoking-related variables, and the severity of the disease. According to the four functions of social support, appraisal support ranked the highest, and the most common source of support was the family members. There were significant differences (p＜.05) between the smoking cessation and emotional support, appraisal support and support from family members (p＜.05, respectively). Especially, there were significant influences in the emotional support (p＜.05), appraisal support (p＜.05) and tangible support (p ＜.05) from family members. The subjects who considered quitting within one month or who successfully quit were found to benefit from social support mostly. Conclusion: Smoking cessation is an active process. At different stages, the target person should be given different types of social support and education in order to aid the target person in achieving his or her goal.