Background: Fatigue, as a destructive phenomenon, can have adverse effects on various aspects of workers' lives. Job burnout is one of the important consequences of fatigue among employees including nurses in different workplaces, especially healthcare centers. Objectives: The present study aimed to assess the relationship between fatigue and job burnout. Methods: This cross sectional study was conducted on 522 nurses, who were randomly selected from teaching hospitals of Shiraz University of Medical Sciences (SUMS), Shiraz, Iran. Fatigue dimensions and job burnout were measured by Multidimensional Fatigue Inventory (MFI-20) and Maslach Burnout Inventory (MBI), respectively. Results: The results revealed that among burnout dimensions, depersonalization and diminished personal accomplishment had the highest mean scores, while emotional exhaustion had the lowest mean score. Among different fatigue dimensions, the highest mean score was related to general fatigue. Moreover, the results of Pearson's correlation test showed a significant positive relationship between emotional exhaustion and fatigue dimensions. Also, a significant direct correlation was found between depersonalization and general, physical, and mental fatigue. On the other hand, a significant negative correlation was observed between diminished personal accomplishment and all fatigue dimensions, except mental fatigue. Conclusions: Considering the adverse effects of fatigue on various aspects of nurses' job burnout, more attention should be paid to fatigue in healthcare facilities, especially hospitals. In addition, a suitable managerial program should be developed to decrease nurses' job burnout and other fatigue consequences and to improve working conditions.