Background: Based on the data Global Tuberculosis Report (2015), Indonesia is in the second world rank for pulmonary tuberculosis patients after India. TB preventive behavior is done to reduce the rate of TB transmission to people in the neighborhood. Knowledge of prevention of transmission of TB is the main provision to prevent the transmission and spread of pulmonary tuberculosis. Objectives: The purpose of this study was to determine the correlation between knowledge of pulmonary TB patients with behavioral prevention of TB transmission in Bantul. Method: This study was correlation study with cross-sectional approach. Thirty one respondents were selected through total sampling. Inclusion criteria were TB active patients in puskesmas Sewon II and Kasihan II. The data were collected by using TB knowledge questionnaire and TB prevention behavior questionnaire. The data were analyzed by using somers’d test. Results: The results showed that the most respondents had good knowledge (61,3%), and most respondents had good TB transmission prevention behavior (77,4%). The results of Somers’d test value was p = 0.004 (p < 0.05). Conclusion: There was a correlation between knowledge of pulmonary TB patients with behavioral prevention of TB transmission in Bantul regency. Nurses is suggested provide health education to cultivate a positive knowledge. So, more patients with pulmonary tuberculosis can prevent the transmission of their disease.