This study aimed to investigate the impact of authentic leadership on organizational bullying with the mediating role of organizational culture. This research is a descriptive correlational study. The statistical population included all the staff that worked in 1396 at Lorestan University which consisted of 575 people. The sample of 234 people was chosen using proportional-stratified sampling method. For data collection questionnaires of authentic leadership by Walumbwa, Avolio, Gardner, Wernsing & Peterson (2008) with alpha (0. 91), organizational culture Cameron & Quinn (2006) with alpha (0. 92), and organizational bullying Einarsen, Hoel & Notelaers (2009 with alpha (0. 95) were used. To analyze the data, we used leas squares structural modeling employing Smartpls 2 software. The results show that authentic leadership has a direct impact (β =-0. 655) on organizational bullying. Authentic leadership has a direct impact (β = 0. 599) on organizational culture. Organizational culture has a direct impact (β =-0. 280) on organizational bullying. Besides, the impact of authentic leadership on organizational bullying directly (β =-0. 655), indirectly (β =-0. 167) and by mediating role of organizational culture (β =-0. 837) were explained. It can be said that authentic leadership with the mediating role of organizational culture decreases organizational bullying among employee.