Introduction: Two major aspects of knowledge management for gaining competitive advantage in organizations are organizational learning and organizational forgetting. Despite several research studies on knowledge management and organizational learning, a few studies have been performed on organizational forgetting and its management. In this study, it was attempted to introduce a conceptual model of organizational forgetting and to investigate its relationship with change-oriented and pragmatic leadership styles.   Methods: The present survey was of fundamental experimental type, based on correlation method adopting sampling technique. Managers and vice-chancellors of private and public hospitals in Tehran formed the population of this research. The data were analyzed by LISREL software using structural equation modeling.   Results: Although both leadership styles had an influence on purposeful organizational forgetting, change–oriented leadership appeared to be more effective. Furthermore, the effects of various variables on pragmatic leadership and change-oriented leadership were obtained separately. It was found that short-term thinking of the leader with a factor loading of 0.89 had the largest effect on pragmatic leadership and encouraging and inspiring of the leader with a factor loading of 0.92 had the largest effect on change-oriented leadership.   Conclusion: Comparing the effects of change-oriented leadership and pragmatic leadership styles on purposeful organizational forgetting, the researchers suggest to apply change-oriented leadership style for optimal management of purposeful forgetting.