Purpose: Patients with pulmonary disease are more vulnerable to Particulate Matter (PM). It is important to promote health behaviors to minimize negative effects. This study aims to investigate risk perception, knowledge, and PM-related health behaviors in patients with pulmonary disease and identify the factors affecting PM-related health behaviors. Methods: Participants were 201 patients with pulmonary disease who visited the outpatient clinic in a hospital. Data were collected using self-administered questionnaires and medical records from December 2019 to February 2020. The collected data were analyzed using descriptive statistics, independent t-test, one-way ANOVA, Pearson’s correlation coefficient, and multiple regression analysis. Results: The average score of PM-related health behaviors was 22.79±4.43. In multiple regression analysis, factors affecting PM-related health behaviors were participants with higher risk perception of PM (,p<.001) and with longer pulmonary disease (p=.006). Moreover, participants who smoked previously but not currently (p<.001) and had never smoked (p=.001) had higher level of health behaviors than those who smoke. Conclusion: Patients with pulmonary disease reported to have high level of overall PM-related health behaviors, but their performance on health behaviors that required knowledge was reported to be insufficient. Therefore, a patient-tailored educational program is needed to improve PM-related health behaviors by emphasizing risk perception related to PM. Special attention should be given to smokers and patients who experience a short disease period to improve PM-related health behaviors.