Purpose: The purpose of this descriptive study was to identify factors influencing pulmonary tuberculosis patients’ self-care behaviors. Methods: The patients were 125 adults over the age of 19 who were diagnosed with pulmonary tuberculosis, receiving care at the National tuberculosis hospital. The survey questions measured family support, multidimensional scale of perceived social support (MSPSS), stigma and self-care behaviors. Results: The average score for self-care behaviors was 3.91, ranging from 2.22 to 5.00. There was a significant positive correlation between self-care behaviors and support system. There was a significant negative correlation between self-care behaviors and stigma. The significant variables influencing self-care behaviors were family support (β=.33, P<.001), smoking (β=-.23, p=.002), age (β=.22, p=.005) and experience of stopping treatment (β=-.17, p=.040). These factors explain 36% of pulmonary tuberculosis patients’ self-care behaviors. Conclusion: Family support is very important to improve self-care for tuberculosis patients. However, those in their fifties, men, and those who do not have a job and have underlying diseases have low family support, so they need active support at the national level. The study results suggest that a educational and nursing programs must be designed to reduce stigma and promote support system in order to enhance self-care behaviors.